Idaho's Sawtooth Mts are well worth the stop, as is Craters of the Moon Nat'l Monument, if you haven't been there. (That's more south-central Idaho, but perhaps could be on your route.) The McCall area of Idaho is gorgeous!
Camping in/near the Sawtooths is pretty much no-hookup; we've looked at a couple of CGs in/near Stanley with hookups and were not impressed. However, there's a dandy little RV park with water & electric hookups in between Stanley & Challis, called Torrey's. It's on the Salmon River in a canyon (little to no phone service or wifi). Beautiful spot and a good base camp for a few days from which to visit both Stanley & Challis, plus some old gold mining ghost towns and the gold dredge. With no big trees, this CG would fit your rig well. Only about a dozen sites, so reservations advised.
We haven't seen the private CGs in McCall, but if you can snag a site in the RV section of Ponderosa State Park, it's WELL worth visiting. Beautiful wooded CG on a lake, and the RV sites are all FHU, I believe, and just as pretty as the "regular" ones. It's extremely popular, so reservations well in advance are essential.