Hi OP, welcome to the Disboards! We are also a family of 3 (Mom, Dad, and 6 year DD) in Ontario. I think you've gotten some great advice so far. If you're flexible on timing, I'd pick a time when the weather is most suitable for your family. It ranges from surface-of-the-sun hot in the summer to four-seasons-in-one-day weather in the winter. It seems to always be busy at Disney world these days. (I feel like my last Feb trip was busier than my last Dec trip!) You can definitely get a solid vacation for $10K.
I may not be as practical as some of the others on here, so for me, I'd rather drop one night from the trip than pack sandwiches for the park or buy "souvenirs" in advance. The cost of one night accommodation on-site plus tickets for 3 pays for a lot of overpriced plastic junk that will collect dust in your home for years to come

in all seriousness though, I love these tangible reminders of our vacation together. But I do try to keep it down to ONE tangible reminder per trip now because...
The biggest danger of spending $10K on a Disney world trip is that you'll want to go back for another trip! We did a "once in a lifetime" trip in Dec 2018 to Disney world (funny enough, spent about $10K on it as well, although that was 4 years ago) and now are addicted.
Some random thoughts:
- I love December because of the Christmas decorations, so always prefer to go in December if thats an option. Getting away from the cold Canadian winter for a bit is always nice too. But December isn't always reliable for swimming weather in Florida. Late October to early April is probably my ideal, weather-wise. Does it stop me from going in the other months? Nope. I am truly addicted. As Olaf would (somewhat) say, some things are worth melting for!
- Flying out of Pearson lately has been horrendous. Our outbound flight was delayed because of the plane sitting at the gate & not being allowed to unload due to customs restrictions. And on the return trip, you guessed it, we sat on the tarmac for over an hour due to customs keeping passengers on the plane vs. having them run riot through the customs hall. I don't blame them, but it sure isn't fun sitting there with a cranky 6 year old at 8PM. We got home after midnight despite landing at 8.
- With that being said, I'm taking the Leafs' lead to heart and flying out of Buffalo next time. If its an option for you, I'd suggest considering it. Price savings aren't as significant as they used to be, and you have to make sure you allot time to drive & cross the border, but that airport is a joy to fly out of compared to Pearson. I've never flown out of Detroit but maybe thats an option for you too, depending on where you are in Ontario.
- My personal favourite resorts when pushing a kid in a stroller are Contemporary/Bay Lake Tower, Grand Floridian, Boardwalk, and Beach Club/Yacht Club. The first two are walking distance to Magic Kingdom, the last two are walking distance to Epcot (and to some extent, Hollywood Studios).
- Don't be afraid to have some spontaneity when it comes to dining reservations. Getting up at the crack of dawn at 60 days before your trip can be exciting (I'm a planner at heart) but checking the day before has allowed me to snag some great reservations, as people cancel them one day in advance (to avoid the cancellation charge if you cancel same day, or don't show up).
- Look into
Genie+ and/or
DAS if you qualify. I don't know much about DAS but Genie+, if used correctly, can save you a lot of time. There's videos out there on how to use it and how to stack rides.
- I'm too cheap to pay for individual lightning lanes, but if you hop into line right before park close for the headliners, you'll find the wait time is often much lower than what is posted. (Rise of the Resistance is our usual line at park close, we hop in around 8:55 when park closes at 9:00 and the wait time is about 18 minutes to the first pre-show, vs. the 45+ minutes shown.) Wait times are not reliable.
- Ice water is free, but I find it tastes funny at some locations, so I usually bring a water bottle and fill up at the ones that don't taste funny to me.
- Bring an extra battery for your cell phone, you'll need it. Also bring ponchos, I prefer the disposable ones so I can toss them after each use rather than try to dry & fold them up into the neat little square they came in.
- Fireworks are awesome, well worth watching at least once on your trip. If your kid has an early bedtime, consider one of the winter months for your trip, as it gets darker earlier so fireworks at MK are an hour earlier than in the summer months. I don't know if Epcot fireworks hours change, haven't seen that happen recently.
- The MK parade is also awesome. The cavalcades are fun, there's tons of live entertainment, and the atmosphere at MK itself is just magical.
- All the parks are worthwhile. My 6 year old would rank them currently as Hollywood Studios, Magic Kingdom, Epcot, and Animal Kingdom. But the order changes frequently so I wouldn't dismiss any of them out of hand. The resort pool is great too, and kids don't really care if they're in a value or a deluxe.
- If your family is able to stay up late, the extra 2 hours for Deluxe resort guests at Epcot and MK on select nights is fabulous.
https://disneyworld.disney.go.com/en_CA/guest-services/extended-evening/ Highly recommend. We aren't able to get up early enough for the morning extra hours for all on-site guests, so can't speak to that perk.
- Don't forget to make park pass reservations!!!! Book it as soon as you buy tickets. You can always go in and change it around later but I've seen too many posts from people that have their vacations perfectly planned out, and then realized they can't get park reservations anymore. Personally I love the flexibility of being able to hop, so we can end the day with fireworks when we want to.
- Overall, just go with the flow. My six year old changes her mind frequently and being willing to change plans day of allows us to all have a more fun, relaxed vacation. Do I plan everything anyways? Yes. But I'm willing to let it go... sometimes.