Hi Kim, it's Sherry7 from TT.

Fancy seeing you here, lol.

Cinderbelle (Cindy) is around here too on occasion.
Not sure if you know about this, but you can order a case of water from Costco even if you're not a member. It's around $8 or so, shipping included, and it's delivered to your resort and held for you. Water is very expensive in the parks, so it's a good option. Oh, and the tap water from the fountains tastes like swamp water.

If you plan on drinking it, be sure to bring some Crystal Light drink packets with you.
You can also get free ice water at any of the counter service restaurants. The swamp water actually tastes better when it's cold, lol.
Will you have a rental car? The buffet breakfast at Ponderosa is only $3.99, and there are usually coupons for 10% off that in the various brochures. Even though I won't eat my $3.99 worth, DH and DS definitely will. The drinks are fairly expensive though, but ice water is always a free option.
I'm not sure about the cooler in the park thing works, since we haven't done that. We got tired of carrying a small backpack along, so a cooler definitely wouldn't work for us. In the past we just had a big breakfast at Ponderosa, a small snack later on, and then had dinner somewhere off-site.
Since my food options are limited like yours, I plan on bringing along some snacks for myself...beef jerky, dry roasted edamame, almonds, protein bars, etc.
Can you tolerate hamburger? If so, a double hamburger is just a bit more than a single hamburger. You can always eat the extra patty from one of the family members portions. I believe you can also buy an extra bun, if you ask. That would be a good way to split a meal between 2 kids.
We're going in January, but decided to rent a condo instead of staying on-site. I was surprised to learn that it was a lot less expensive than even a Budget resort.
When you get back, please PM me on TT, and let me know what kind of gastric bypass friendly food you find in the parks. I'm rather worried about that.
