5 & 3 or 4 & 4 nights…haven’t decided yet, but do you have any recommendations for packing so that I don’t go crazy mid-trip during the switch?
I do two suitcases.
Funny, I do two as well but I end up with clean/ dirty bagged clothes. That way I have all clean clothes in one suitcase for the move ( shoes go in the suitcase with dirty clothes as well).
I pack in ziplocs so dirty things are in a sealed bag, but I put toiletries and extras in one piece of luggage and then the other two are split by hotel stay!
I always have good intentions, but I always end up needed something from the other suitcase and therefore tear everything apart! Then I shove it all back in and move resorts.
I think this is when ebags packing cubes can be helpful. They go straight from suitcase to drawer and when you need to repack, from drawer to suitcase…
100% use packing cubes they make life so much easier! And your clothes dont have to touch the icky drawers 
We have done three split stays and packing cubes changed the whole experience last year . I would definitely recommend them. We are swearing off split stays this year I need to just stay put and relax. It’s a great way to experience two resorts but it does eat up time.