That's an interesting question regarding what room accommodations might work best for your group. I would think a studio is way too cramped. I'm even wondering if with your family make-up, a 1BR could be too small. I believe the 1BRs at Boardwalk have space to sleep 4 - a kind bed in the master bedroom and a pull-out sofa in the living room. Sleeping 5 could be tough, even with 2 youngsters. A 2BR would be great (sleeps 8), but probably very expensive and more room than you might require! So it might depend on how amenable the girls are to sleeping on the floor. A big advantage (at least we think it is) of the 1BR or 2BR is you have an in-room washer and dryer - it can make packing requirements easier sometimes.
I don't have experience with renting points, but many people do it and save money - and also get their rooms booked a little earlier (if you find a person to rent from and give more than 7 months notice). During a normal spring, March would be the Flower and Garden activities at EPCOT, and BW would be very popular for the ability to walk into EPCOT - not sure if that will be as important March or 2021, but I sure do hope so!
It cannot hurt to check with a rental company to see if renting points might be a good fit for you, and what it would cost. You are now approximately 7 1/2 months to 8 months from your desired dates. And if you can find an owner at BW looking to rent, the availability prior to the 7-month mark would be much greater. At 7 months, all DVC owners can book at BW. Best of luck with your plans. I know how disappointing it is to be cancelling upcoming fall trips this year. Looking forward to more normal times again!
