How long would you let your LO fuss as they wake up from a nap?

C is 6.5 weeks. She has been on and off fussing for more than half an hour, but just as she actually cries and I get ready to go in and get her, she quiets down again. I figure this is good for learning to self sooth, even if she isn't quite going back to sleep? Kind of annoying because I had a phone call to make that I definitely had time for, but I kept thinking she would lose it at any minute. She hasn't actually cried for more than a minute at a time, it's mostly just moving and making noises.

This kid likes to keep me on my toes.