Help Plan Road Trip - Montana -> California

Need some help putting together a good route for a road trip. I will be driving my truck from California to Montana, that leg of the trip will be a straight shot. After I get some work out of the way, I will start a 10 day road trip from Montana back to California.

The plan is to go through Idaho, into Oregon and then back down to CA. I would like to see / get into some remote areas. It's just going to be me and the gf, so while I do want to get into remote areas I'd like to keep it somewhat sane, no super crazy off roading. My truck has sliders, a 2 inch lift and 265/75/16 Duratracs. That's about the extent of the mods.

Do you guys have any good routes to suggest through these states? Would prefer to have the route go from east to west and back down south. Any must see spots, fishing stops, food I must eat, etc.?

Lastly, I'm not looking to camp in designated camp grounds if possible. Maybe one or two to get a hot shower but otherwise would prefer isolation.

Thanks