In reply to Andy 976853:
I can't give you any details, but I think the key is canal towpaths. You could do something like:
-Mam Tor/Rushup edge/various footpaths to Whaley Bridge.
-Pick up Peak Forest canal towpath to Marple.
-Macclesfield canal to Kidsgrove.
-Trent and Mersey Canal to Middlewich
-Middlewich branch of Shropshire Union canal to Barbridge.
-Main Shropshire Union canal to Chester.
-Pick up Wales Coastal Path on the banks of the Dee at Chester.
-Follow Wales Coastal Path to Conwy.
-Dig out your 1:25k OS map. There are lots of ways down the Conwy valley - my personal preference would be to stck to the western side. You can climb up behind Rowen and stay a good 100m above the valley floor just about the whole way to Betws.
No idea how long that is, or if it could be conveniently made shorter by going cross-country between some of the canals when they wind around. However it gives you an idea of where to start looking for B&Bs