Until your youngest is over 3 my understanding is many 1 bedroom villas will allow 5 + 1 under 3 In a pack and play (which are in the rooms). So that could be an option for your family vs a 2 bedroom at least for a few years. Unless you are huge VGF fans don't compare the point cost of a 2 bedroom there with 2 studios at the Poly but use another resort like BLT or even VWL for comparison. Few thoughts on the laundry and kitchen: I never expected that they would be such a great thing for us. Our family of 4 usually stayed in a room at a deluxe resort so we thought we'd be fine in a studio. But since we bought DVC have only stayed in a 1 bedroom. Our first trip was a "splurge" then we couldn't go back! I rarely cook but we do always have breakfast in the villa now and sometimes a light dinner like salad or sandwiches. Having space for snacks, drinks, plus a table to play games is a huge bonus. The washer and dryer in the room are an extra bonus - I never did laundry before but it's so nice to throw in the towels or some of the kids clothes while we're doing something else. With DVC you don't get daily cleaning or fresh linens unless you pay extra so it's nice to be able to wash the towels ourselves and have fresh ones daily or every other day. Also as many others have posted, your kids will grow up quickly and 2 studios may not always suit your needs. One thing I noticed when we toured the Poly is the lack of storage space for suitcases, clothes, etc. - not bad for a couple for a few days but could be an issue for a family of 6 for a week.
For disclosure - we own at AKV and are a family of 4 with 2 tween girls. Regular rooms were fine when they were younger but as they've gotten older both they and DH and I appreciate the space that a 1 bedroom affords. AKV Kidani and BLT 1 bedrooms have 2 true bathrooms (master with jacuzzi tub, shower, toilet and sink, second with tub/shower combo, toilet and sink)....2 bedrooms have 3 bathrooms in AKV Kidani and BLT. Poly has "2" bathrooms per studio but one has a shower and sink and the other a toilet, tub/shower combo and sink. Just another consideration if you have girls

! We would have added on at the Poly had they had 1 bedroom villas because we love the theming and the location.
My suggestion for you is to really research all the resorts. Look at the layouts and
point charts. Determine if you plan on going every year or every other year. Will you fly or drive? We love AKV but we live close so we drive, making it easier to get around and not have to use the buses. There are pros and cons to buying at the Poly as well as buying resale at a different resort. Just realize they are there and find what's best for your family. Since you are not a current owner, the window to purchase Poly is coming up soon. My recommendation is to research all the options and wait until the booking window opens in a week or two for current owners. Hopefully that should at least answer the question about booking 2 connecting studios as a single reservation. Personally if that wasn't a guaranteed booking category I wouldn't risk it with kids. They won't let the kids stay on their own of course but it would mean you and your DH would be in different rooms.