In reply to Tony the Blade:
There are good options in the Glenfinnan/Rough Bounds of Knoydart area - starting and finishing at Glenfinnan (or at Kinloch Hourn)
e.g. Glen Finnan to Glen Dessary to Loch Nevis to Loch Morar to Glen Pean to Glen Finnan.
There are several bothies on the way, and several more a little further afield, and while as said they'll mostly or all be closed, most have areas near them you could camp.
Just watch the burn crossings if it's wet. Although, it'll be generally miserable if it's wet, anyway!