My bet is that you'll get as far as Portland and then be stuck. I-5 through PDX can be a mess on a regular Monday. Get south of Portland on Sunday and you might

My bet is that you'll get as far as Portland and then be stuck. I-5 through PDX can be a mess on a regular Monday. Get south of Portland on Sunday and you might be ok. The Spokane option might work but the unknown there is that most of the roads in Oregon will be one lane each direction with hundreds of thousands of visitors expected in that area.