Looking for thoughts and advice on toddler sleep.

Background- C is almost 23 months, generally is an ok sleeper (STTN in her crib, almost always takes at least a 1.5 hour nap). We have a queen bed in her room (former guest room) as well as her crib. When she wakes up in the middle of the night, most recently seemingly from a nightmare, DH or I will go and lay down with her in the bed and sleep the rest of the night like that.

Recently, maybe every other week or so, she has a night where she just will not go to sleep, crying and yelling no matter what we do, until finally one of us lays down in the bed with her and she goes to sleep there. We move her to the crib an hour or so later.

I really don't want to move her to a big bed yet, her room isn't totally baby proofed, and we were just planning to wait a few more months. But I'm wondering if it's coming sooner than I thought and I need to accept that. Anyone experience something similar?

We also have a new baby coming in dec, who will share the room with C eventually by will be in our room for the first several months. We could borrow another crib or give the new baby C's crib.