Split stays at WDW are extremely uncomplicated, compared to most travel.
Our family took a trip to Ireland once, where we drove around and stayed in 6 different bed and breakfast places, in 6 different cities, over an 8 day period. Every morning we needed to pack up, drive to the next city, see some sights, and then check in at the new B&B, and none of them were associated with each other.
We recently took a trip to the Mediterranean. Over a 10 day period, we stayed in Barcelona, Rome, Florence, Genoa, Paris, and then back to Barcelona. We took public transportation and had to handle all our own baggage, including getting it all onto the taxis with us. Since there were 12 of us, we needed 3 taxis or Ubers to go anywhere. And we also sometimes used the trains and subways. At one point 4 of us were walking down La Rambla at 1:30 in the morning, pulling our suitcases behind us for over a mile. And one time we had to haul all our suitcases about 1/2 mile in a pouring rain, from the subway station to our hotel, since all the taxi drivers were on strike.
So, how hard can it be to do a SPLIT STAY at WDW? Anyone who complains about that or says that it is too hard is SPOILED.
For a split stay at WDW, what do you do? You pack up your suitcases on the day you change resorts. You call Bell Services to come pick them up, and you gave them a $10 tip and tell them which resort you will be going to. You go onto your phone or online and check in at your new hotel. You get on the bus and go to the park. When you come back in late afternoon, you finish check-in, go to your room, and call Bell Services to bring your stuff up. IF YOU HAVE GROCERIES OR FROZEN THINGS, THEY WILL EVEN TAKE CARE OF THAT.
Let's face it, guys, this isn't very hard. Or complicated.