I’m Canadian. We’ve done two USO trips. My vote is you wait.
1. If you’re really only going to do HP, you might be able to enjoy yourself but if you’re planning on doing more than that (especially on the last day of your holiday), you’re going to feel rushed and you’re likely going to miss lots.
2. Check your kids heights and ride heights. At the ages you’ve listed it’s possible they might be too short for FJ and Hagrid’s at least.
3. I’m assuming you won’t have EP or EE since you’ll be staying off site? EE really makes a difference for both sides of HP, especially if your kids want to do the interacrive wand spell stations. You’ll want the time when the areas are the least crowded. And do note, HP on both sides, still do get quite crowded (bordering on unenjoyable in our opinions - at least in midday hours).
4. It looks like if you’re going in 2022 your one child will be 11? It’d be the perfect time to get his Hogwarts letter and do the trip. Also by that age you’ll ensure that they are both likely tall enjoy, brave enough, and mature enough to enjoy everything the parks has to offer outside of HP.
And, most import (IMHO), depending on the time of year you go, as a Canadian you’re going to get pretty good deals if you book a hotel and tickets through OSU. As a CDN, for the past three years at least, you get offered the “unlimited ticket” if staying at the hotels and booking tickets through them. This ticket gives you P2P for 14 days, and also includes VB. They also give you a $50 “resort activities” credit, which we used for 2 days of meal plans which can be split between everyone and used over the course of the trip piecemeal (doesn’t have to be used in one person and one day, actually have a year to use credits). We also had the option of using the credit to book the HP breakfast, Blue Man Group, mini putt, dinner show, etc. You also will have the option to upgrade your tickets onsite to an AP or like $50, if I recall correctly. And you’re given a coupon book that gives you about 30% off nearly every restaurant on CityWalk and some other benefits and discounts as well. It also gives you priority access/seating to some shows. Since you’re staying at a USO hotel you’ll at least have EE - Cabana Bay, SF. Pretty much anywhere else you’d also have an EP for your stay. We tend to go the week after American Thanksgiving. We stay in a family suite (bedroom, living space with pull out, kitchenette and divided bathroom and LARGE walk in closet) on the poolside in the “courtyard” area. We’ve done a 10 day vacation. Including that deal through USO (hotel and tickets and some food), AC airfare and a car rental on Expedia - we were about $1350/person. So I definitely feel like a you could use your $1000 in a better way. We also feel that doing USO really does need more than a day. We’ve had 2 vacations there at this point and there’s still lots we haven’t seen (though we also tend to only go to parks a few hours per day, have pool afternoons, take advantage of VB, visit a shopping outlet and have often gone and done “free” or cheap things at Disney - eg. DS, dinner reservation at one of the hotels, do a tour of the decorations and Christmas trees at their hotels, do a Disney mini putt or one on International Drive, etc.).
