for our upcoming trip, we have 6 nights booked at the Dolphin, followed by 3 nights at the Contemporary. I don't think we could ever choose the MK area over the Epcot area, we love the atmosphere at both! Our switch day, I plan to ask for a late check-out from the Dolphin. I'm entitled to 4pmas SPG Gold, but I don't think I will need that long....that day is planned as an off park day. the late check out will allow us to sleep in, enjoy a nice breakfast and maybe take a swim before moving to the CR. the check in time is 3pm there, so I hope we can time it "just right"

if not, we'll get snack and hang out at the resort, not a biggie.
I don't know if I would do it for just one night, though. I'm not sure if I would feel like I am getting my money's worth, unless you check in really early and have a separate pool bag.
just returned from a non-Disney trip - 3 nights in one city; 2 nights in another; 3 nights in another. I'm the mother in a family of 5 people. I will tell you that it was a PAIN
I just did this for a trip to Washington, DC...plan was one travel night, 4 nights, 2 nights, then a travel night. I was mentally prepared for that, LOL....our plans changed & we ended up 1 night, 1 night, 3 nights (homeless for 3 hours with 3 kids, ugh!), 2 nights, and then 1 night. Thank God I didn't overpack this time, LOL....it was a real challenge!
Anyway, to answer the OP question...for one night? I don't know if I would switch to a deluxe (mainly for the $$), I would consider the S/D or a WDW moderate, though.
good luck!