Depending on what part of December, two rooms at a Value resort will be less expensive than even Port Orleans - Riverside.
They charge $15 a night if there is a 5th person using that trundle bed.
With three children and only two adults they will guarantee connecting rooms.
You can also ask, although not guaranteed, for a King Bed connecting to two doubles. They have some of those room combinations. The King Bed rooms at All-Stars are handicapped accessible and even have fridges. But I repeat, unless you NEED a handicapped accesible room, this combination is not guaranteed.