Definitely Fantasia Gardens, because of the difficulty getting from W-S to DTD, especially when BB is closed.
If BB is closed, the only bus to/from W-S is the Epcot bus, and there is never a bus between W-S & DTD.
Hopefully, DHS will be open when you head to FG. Just take the bus from Pop to DHS, and then the boat to the Swan. If DHS is closed, next best choice is bus to MK & bus to the Swan. You could also take a taxi from Pop to FG; they're close enough that the fare should be under $10.
When you are done, walk back to the Swan and take the bus direct to DTD.