I'll try to answer this as much as I can, I've only been 3 times and each one was staggered out 13 years apart, but I've done so much research and planning I'd like to think of myself asan intermediate expert! Lol first off.. Welcome! This is the land of the obsessive over 1.5 years away and yet planning group. Lol I say that loveingly! We decided on port Orleans, riverside for our next trip mainly because as u said, we don't spend a lot of time at the resort. Last time it was just DS, who was almost 8 and myself who went and we did jan 2-11th, 2014. This time the hubby has been convinced to come with and although he screams he's excited, he is sooo not a planner and basically thinks I'm crazy right now! He's never gone before so I have him the websites I used and said, be free to take a look. We jumped between POR and AOA and a split stay. We wanted AKL savannah fries but just couldn't justify the increased cost of it. This time were there dec 1-13th. Last time I went it was just after Xmas and the Xmas stuff was just coming to a close, we missed candlelight processional and
MVMCP but was able to see the Osbourne lights. This was my main reason for changing the dates this time around to do more of the Xmas stuff. I've read that it's best to do ur must do's leading up to Xmas Eve and Xmas day as it's pretty wall to wall people in the parks but it stays busy till about the 2nd. The dates for the entire year, the rack rates as their called come out July 30th however you can only book 499 days in advance. I'll be under that for my arrival day so I'll be able to book but if your arrival day is more then 499 days you basically have to wait until ur 499 days away to BOOK YOU CAN STILL LOOK AT RATES THO!! And it will give you an idea of what it's going to cost you just can't put down the deposit.
As for the dinning plan, I was set on using it when I first planned this trip cause it was cheaper with just the DS however with the hubby wed actually pay more for the
DDP then we would OPP. And as he said we'd be locked into making sure we had at lest 2 big meals a day. When the son and I went we only did 3 table service meals and I took food for him, mainly sandwhiches and snacks which kept the cost low. If you google DDP calculator there's a site that comes up that you can figure out the cost and it asks for ur dates and you pick ur restuarants for each day, not specifically ur actual plated meal. The great thing is it tells you when ur ADR windows opens so you know when you can start booking meals.
As far as harry potter is concerned. It's the reason I went to disney in January. Sons a massive HP fan, went as him for halloween, he's now 8.5 and he's read the first 5, seen the first 4 movies. It was suppose to be our once in a lifetime trip.. Funny how that happens eh! So I made sure we spent 2 days at universal to make sure he got to do it. He was actually more excited about seeing harry potter then anything else! And we loved the butter beer!! Knowing that and the fact that the new section has just opened I would highly recommend time there. However the way I would do it, and it's just my opinion is to do 3 days, 1 day each for the harry potter section and 1 day to finish off the rest of the 2 parks, especially if ur girls are fans. When I started planning this trip I looked at doing a split, so many days at disney and so many staying in side at universal. If u do universal I highly recommend looking at the cost of staying on site, you get early entreance to the park and complimentary skip the line passes (which can be 89 plus dollars) bought otherwise. I was gonna do this but decided on a whole universal trip in 2016 and to focus on disney this time around. I'm not sure if ur driving or flying down, if u fly and don't rent a car, it cost us about 32-36$ EACH WAY to taxi from our disney hotel to universal and back for 2 days. Which is why the thought of staying onsite next time around was soo appealing!
Let me know if u have any other questions and welcome to the crazy hut!!