A road I've been thinking of doing is the old route from Rossland to Christina Lake. Ussually don't end up going through Trail on my way to the Kootenay's though.
The KVR right away or is this another trail?
To the OP, there are lots of places to camp and explore just off of the highways there. This is a decent resource of what might be of interest on the route: Crowsnest Highway. There are a few good ghost towns along the road too.
Ghost Towns of British Columbia
Ghost Towns of British Columbia, Canada
This is old school video, but Bill Barlee has to have been one of the best historians on mining and ghost towns in BC. Here's a google search of all of his and Mike Roberts' shows of Gold Trails and Ghost Towns: Bill Barlee Gold Trails and Ghost Towns. - Google Search. I use to love watching them on CHEK or CHBC.
Old Cascade Highway Rossland to CL.