Thank you all for the tips - I will check out the Esterbauer guide and You Tube clips - our mileage is a lot less than most cycle tourers (prob max 40 km per day) so just need to work out if there are camp/water/food opportunities close enough together, though happy to do a bit of wild camping! Also I saw something on the Via Claudia site about getting a bus with bike trailer over the two big passes which sounds great for us, although it sounded as though we'd have to book in advance - not so great as really like not to have deadlines!