This question will probably get moved to the 20,000 (at least it seems like 20,000) page occupancy thread! Official numbers are 4 in a studio and 1 bdr and 8 in a 2 bdr. However as many, many members including myself will tell you, member services will let you book 5 in a 1 bdr. However, they will tell you at the time that no additional bedding will be provided for the 5th person but you can request it for an addtional charge. You can bring an aerobed and sheets for it. MS (member services) will put all 5 on the ressie and you will get 5 room keys. Now, with a studio, I really don't know. MS told me "4 in a studio, 5 in 1 bdr and 8 in a 2 bdr". If they only allow 4, one of your kids would not have a card for EE and EMH because they might not list them on the ressie. I don't think you could do 5 in a studio, but the person you rent from can always check for you. You could always rent enough points for a 1 bdr!
PS we love the POLY too!