Hello Newtoyorks, So yes I've done this twice and actually was strangely doing it a third time but only got as far as Middleton on the third occasion due to a knee injury which forced me to abandon...anyway yes, we used a mixture of campsites and wild camping on each occasion. It does take in some of PW and I guess camping will depend on how far you want to walk each day. We found we had to divert slightly on occasions but we got train to Settle then walked directly to Horton to the campsite there, and yes Chris is eccentric - have known him for many years and he doesn't change, but beware this campsite can be very noisy and busy if you hit it at the wrong time. Sometimes music is played fairly late........and if you land when three peakers are doing charity walks then its busy but that said it can be fun. However, little alternative.
Next to Buckden - there is a great little campsite here at Heber Farm, a couple of tea shops but the pub was closed last time. Stiff climb out of Buckeden.
Gunnerside coming out of Askrigg - there is a campsite at Askrigg, and at Gunnerside you can camp in the farmer's field here and there is a pub and a cafe but I bypassed this and diverted to Usher Gap nr Muker - great campsite at Usher Gap, Farmers Arms in Muker also a great pub. You can then pick the track up again out of Muker
The route takes you to Bowes I went here once then next time bypassed as facilities limited and went directly to Middleton. I think the campsite may have closed now. Pub on and off, and no supplies.
To Middleton - there are two/three campsites in Middleton and various pubs, etc. so you can stock up on supplies. The main campsite has a small backpacking area, the site is busy with caravans though and a club on site.
Then to Westgate......first time I wildcamped on the moor about a mile out of Westgate - but there is a good little campsite at Westgate, and a shop. I used this next time.
On to Blanchland - no campsite in Blanchland but if you come out of Blanchland there is a campsite near LadyCross Quarry which has limited spaces so may need to consider booking (nice campsite though) or carry on to Hexham. Good stock up facilities at Hexham and you can camp on the racecourse if no meeting - however I camped at Fallowfields Dene which I loved.
Then to Hadrians Wall - Greencarts is where I camped one time (there is a campsite and bunkhouse here), and the next time I used Winshields Farm but I guess it depends on how far you want to walk each day - either way both are good and you can get a breakfast at the campsite at Winshields which has a good drying room and also a bunkhouse.
At Greenhead there is a hostel but we camped on the lawn at the bunkhouse in Greenhead.
Alston - although there are facilities here, camping is limited - there is a campsite in Alston at the rear of the scrap yard, but I wouldn't camp here again!. You can push on to Garrigill where you can camp at rear of village hall - there was a small shop here, and a pub which is on and off.
Milburn - nice little village but no facilities so we have wild camped near Greggs Hut and used the Dufton campsite.
Appleby to Kirby Stephen - one time we wild camped on route just before hitting Kirkby Stephen, and the second time we went to the campsite on the other end of town en route.
Garsdale Head - there is a small campsite at the farm at the rear of The Moorcock Inn which is great - basic, right on the river - we camped here on both occasions.
From here to Sedbergh - facilities here but limited camping and we ended up a couple of miles off route at Cross Hall Farm at Cautley which was set up by a young couple at a farm - nice site if you are prepared to go slightly off route.
Then it is to Ingleton - we camped at Dent - great place but can be busy, and after this we headed back to Settle wild camping at Ribblehead on the way.....and then back to Settle.
Hope this is helpful.
FL