You can use
MDE with a swan stay - we're staying at the Dolphin this month and I have it added to my account. It wasn't automatic, but I was able to add it about a week after we made the reservation with the confirmation #. I can't imagine first week of February is so crazy that you wouldn't be able to get ANY reservations or FP+ choices. My husband and I booked a stay over the first weekend in October with less than 30 days to go and I was able to scramble together everything we wanted with the exception of FoP. We could have gone at rope drop and done standby but I knew we were going back so we just skipped it. We didn't get a FP+ for the SDMT until we were in the park but checking for it paid off.