While it is nice to see 2 different resorts during a trip, the hassles of moving from one to the other are not worth it.
Not only would you have to pack and repack everything, but you may have to wait until check in time to get the new room. At OKW where we stay, we decided to switch rooms at the same resort and faced a wait from 11am to 4pm just to check in to the new room.
Then you have to unpack all over again!
Also, you may not get a room that you like as much as the first one that you would have.
With small children who probably get cranky after a busy day, the best thing to do is to stay at one hotel only and maybe have dinner at the other hotel to experience it.
Hope this helps!