I think you'd have to work out the route first in some detail, with some rough distances , then identify likely camping spots. Its not necessarily an easy thing to do
I had a quick play on Fugawi and I could draw a route from Edale to Airton (where Fugawi goes on to another disc). The file is too big to attach and wont shrink without losing definition, though....but its possible to do it.
Look at Landranger Maps 109,110,103,104,98,91,92,86,87,79 and 80. Borrow them from a big library before investing hard-earned dosh - they're very expensive. This gives you a wide view either side of the PW itself You can ride on bridleways, white roads, routes (red dots) possibly canal towpaths and there are some useful cycle routes as well (green dots)
As well as wild camping, there's a few bothies - theres a bunch in Kielder forest for instance and one useful one near Hadrians Wall/Pennine Way
Pic of a sneaky wild camp near the M62 attached - I was entertained most of the evening by a kestrel hovering just in front of the tent, and for extra amusement, I counted B&Q delivery vans on the motorway!!