I'm planning on just a bra.
With DD1 I ended up in just a bra, no clue how or when it happened... I was hot, uncomfortable and well, the clothes went. This coming from a person who refuses to wear shorts in summer as I don't want to show my legs, and up until 2 years ago would refuse to wear t-shirts as I didn't want to show my arms!!
This time I'm planning a home water birth, so not going to bother with clothes.