I'm having the same issue. I wish Disney would post what/when the restrictions for 1-night stays are. All decent hotel chains do - this isn't really a big ask.
I'm looking for 1 night this Friday. There is a ton of availability if I book 2 nights, but only deluxe 1/2 bedroom villas if I want just 1 night. Seems like a big gamble to not fill hotel rooms this close to check-in.