It is very difficult to do.
I started route in Spokane, first stop Mazama on WA 20 east side of North Cascades NP. Forest service campground 1 night, travel time plus stop at Grand Coulee dam
Continue west on WA 20 to Keystone Spit SP. 2 night do to travel time. Day trip to Seattle via Mukilteo ferry.
Catch ferry at keystone spit to Olympic Pennisula. WA 20 to US 101 west to Elwha campground Spend 1 night, visit Hurricane Ridge near Port Angeles
Continue west/south on US 101 to Kalaloch campgound Should visit Tatoosh Head near Neah Bay. Farthest west point in continental US.
Proceed south to Hoquim to US 12, proceed east to La Wis wis campground east of Randall Stay two nights.
Continue east onus 12 to Yakima, I-82 to I84 into Idaho toward Stanley
Lot of windshield time
