Were it just two grownups, I'd definitely say split it up. I'm not sure how young your 2 young ones are. Are they able to help pack and unpack or would one parent need to distract them while the other one does all the work? Do you tend to overpack? Swithing resorts mid-trip would make sense if you're not packing for 16 days worth of vacation and were planning on doing some laundry anyway, as the day you need to switch can be the day you do the laundry and then just move it back into suitcases. But otherwise, bear in mind that at least one grownup, if not the whole family, is losing a chunk of his or her or their vacation doing the work necessary to move. Plan it out in advance so it's a minimum of fuss if you're going to do it, is all I'm saying. Probably would be easier for one parent to "babysit" at one of the parks or take the kids to breakfast whilst the other one throws everything into bags for the switch.