Okay, you have gotten a lot of good advice about watching
YouTube videos. I think you're really getting hung up on use years and borrowing. Not that it isn't important, but like an earlier poster said, you're asking calculus questions when you're in algebra right now. Not trying to demean you in any way, but you're confusing yourself on something that, IMO, needs to be looked into later, because . . .
You need to explore all the one-bedrooms and resort amenities by watching videos to see how much space you need, storage offered for your twins' crapola, bathroom setup as you have three girls needing mirrors and showers, etc., and anything else that is peculiar to your family setup.
Do you plan to cook to save money? Do your kids like to make snacks or their own breakfast? Some kitchens are better than others in terms of layout and functionality and having drop zones for shoes, backpacks, ears, cups, etc.
We LOVE one-bedrooms (and larger,) and will not do studios again. If your husband is hesitant to do Disney, having a bedroom for privacy and sleeping in as you quickly approach the teenage years is a really big help for turning him into a convert. I say this from personal experience;-)
One-bedrooms are the easiest category to book in any resort, which helps grabbing those hard-to-find rooms at resorts peak times (hello, Christmas, April vacation, and Thanksgiving) BUT, if you aren't booking your home resort at 11 months, you almost certainly will have to book a one-bedroom at the most expensive view option at the 7-month window. Those can eat up your points really quick, especially if you're thinking of a small contract for banking and borrowing.
Staying
DVC changes your park habits. Whereas before you may have been park warriors out from dawn to dusk, now you'll find you like to do more resort-only stays or pool days. This is where home resort advantage and preferences really comes into play.
We have done the last week in August twice now, and while I am fine with it, it IS brutal with the heat. There's no way we can handle more than 3-4 hours at a clip in that heat, so that means we're poolside and trekking back and forth from the resort to the parks and back again. It's too freaking hot to be dealing with transportation all the time or walking far to get food or ice cream, so that means (for us,) we want amenities on site -- preferably all with AC. While Riviera's pools aren't exciting, the on-site bar, Primo Piatto, gelato cart poolside, and Topolinos for drinks and dinner at night -- all in AC -- make it far and away our favorite. If you're planning on buying and holding, don't rule it out because of resale restrictions. We plan to pass our Riviera points to our kids (Irish twins, b/g age 9 and 10.)
Now, Riviera is tough in late summer for Skyliner going down due to weather, which is true. We only had it go down once in rain on our trips, but it is a factor to consider. However, during the hurricanes recently when people were in lockdown, Riviera and Copper Creek and Jambo got rave reviews for having really good dining and entertainment for the kids during that time. So, YMMV. I'd rather be trapped at one of those three during a hurricane and eat well and not be stuck in my room the whole time.
I wouldn't rule out BW. It's getting a refurb this fall and tons of new dining, coffee shop, bakery, deli, and it's walking distance to two parks. We toured it this past December and fell in love with their actual boardwalk vibe and lovely walks around the lake at night, grabbed a drink at Abracadabar, shopped, and just took it easy. A smaller resale there could be awesome to dip your toes in. And, as a bonus, we really liked their pool with the roller coaster theme! We loved it way more than BC/SAB, but it's good to try for yourself. BW pool never gets love because it used to have Pennywise as the exit to the slide, but now that it's rethemed, it's lovely there.
BC has SAB, which we were glad to try, but find somewhat overrated. But, again, you need to look at it and see what you think. Also, our kids are on the swim team and older, but that pool would give me a heart attack with kids who aren't strong swimmers and/or littles. Wayyyyy too chaotic, easy to lose sight of your kids, deep water, few chairs unless you camp out earlier -- too crazy for more than a day there at their pool, IMO.
Which parks are your favorites? We are Epcot/HS folks, but for many MK is their dream. We ruled out Poly due to only studios and bungalos, but after staying at GF one-bedroom this Christmas season and monorailing over to Kona for breakfast, we all fell in love with the grounds and pools and general vibe at Poly. We're saving up for Poly 2.0, even though MK is our least-favorite park, because it will be a self-contained tower with a variety of room options, on-site dining, and tons of awesome other dining easily accessible by walking to GF/Poly 1.0 or taking the monorail to BLT or even Epcot, if need be. That will be our holiday choice for Thanksgiving to enjoy the holiday decorations but NOT being at GF.
GF is the most expensive, and while beautiful, holy crap it was mobbed 12/10-12/17 when we went. I can only imagine actually being there Christmas week to NYD. The dining options are great, but they're not IN the DVC building, so you have to be dressed and functional to get food, plus navigating weddings and looky-loos and folks wanting to take pics and propose in front of the tree in the main building . . . it's a lot, and we found it draining. The monorail was also smelly, a little inconvenient to get to (going outside, upstairs inside, battling crowds on staircases and the birdcage elevator,) and it broke down, stranding one party at Contemporary. Not saying it's not helpful, but I think it's overrated as a means of transportation. But, we're biased towards the Skyliner, so take this as just my two cents.