Alaska Airlines has round-trip flights from Seattle (SEA) to Salt Lake City, Minneapolis, Atlanta, or Detroit (SLC, MSP, ATL, DTW) for $85-$157, NONSTOP. Flights November to March. Weekends available. Origin/Destination reversible. No Thanksgiving dates.
Some small OTAs on Skyscanner have this for cheaper than the airline. If you plan on booking there, beware of any site that charges a fee to cancel a ticket within the 24-hour “free” period. Use unknown booking sites at your own risk.
A Carry-on bag and also a personal item is allowed for free on Alaska Airlines. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.

