When we visit all days are park days, we go to all 4 Disney Parks and Universal. This year will be 7 with
Epic Universe. The only days we don't go to a park is the day we arrive and the day we leave. So, exactly for this reason I hate split stays, we've only done it once and I don't think I want to ever do it again.
We don't bring groceries back to the hotel, maybe some drinks and snacks thats it, we have breakfast, lunch and dinner at the parks. Unless, Disney started offering a service where they bring all your stuff from one hotel to the next, where you could drop off your luggage very early, then just head to to the other resort after and grab your key split stay is just not optimal for us.