If you don’t mind a redeye, and flying for just about 24 hours round trip, this one will work for you. The lowest rate seems to be from MIA but your are at just about the same number from SEA with a HT to TFD for the find.
It seems, from ITA Matrix anyway, there should be some weekend only dates but I could not find them. Worth a look other months.
Here are the numbers from MIA:
6,369 MQMs at 4.4CPM
Bookable on Delta.com