We love split stays! We have only done them with kids, but it's generally the same (other than the late-night aspect suggested by
@Sandisw):
We usually schedule a late morning brunch at the check-out hotel - could sleep in and pack before then, or enjoy the pool, or go to early AM EMH if they exist... at AKV I'd recommend Boma, at VGF maybe 1900 Park Fare or Grand Floridian Cafe. I'm not super familiar with brunch options at CCV since I haven't stayed there, but you could take the boat to the Contemporary and go to the Wave for breakfast, or California Grill for brunch if the dates work out (Sundays only, I believe).
We check out by 11 and rely on WDW luggage transfer (bring bags down to bell desk) and keep a day bag or park bag, and then go to brunch.
After that, we usually go to a park that is somewhat close to the check in hotel, and schedule an early-ish dinner at that park or at the check-in hotel. That way, if there's any delay in the room being ready, you're not really noticing it. If you get the text early, great, if not, you are having a nice dinner somewhere anyway. For check-in dinners:
AKV: Jiko or Sanaa (or Boma), or do a dinner package and Rivers of Light at AK (Tiffins, or Nomad Lounge)
VGF: Citrico's, Narcoosee's or 1900 Park Fare, or dinner at MK - Be Our Guest, or California Grill and fireworks....
CCV: Whispering Canyon Cafe, or dinner at MK or at the Contemporary.
The other advice I'd give is to not overpack - if you're not staying more than 2-3 days at each place, then pack at most 4 days' worth of clothes, and do (free) laundry the night before or the morning of each checkout, then you can just toss the clean laundry in your suitcase again.