For a U.S. citizen to enter Canada:
A driver's licence is not technically sufficient but the passport is not required.

What is required is proof of citizenship, or at least of birthplace which can be taken as evidence of citizenship (I'm assuming your birthplace is in the U.S). Your licence doesn't show either. A birth certificate and driver's licence should be sufficient, both ways.

I don't think an expired passport is a good thing to use. It will lead to additional scrutiny and boring questions about why you are presenting an expired document...

Have a good trip.
W-O