Washington services we found quite reasonable. There's a back entrance from the lorry park (where caravanners usually have to park) which saves some walking! It involves a couple of flights of stairs so not good for disabled access. We used Bowburn services once but never again, especially in hot weather. The lorry park smelled worse than most urinals! Tried Aycliffe services once but there didn't seem to be anywhere suitable for caravan outfits.
Once you pass Washington northbound there's not much else until the Stannington Services. My passenger wanted to stop at the Metro Centre, but the driver didn't co-operate.
How about the CC club site in Stockton? If you turn off the A1 at Dishforth and come up the A19 instead, (its certainly no longer) the campsite is less than 5 minutes off the A19.
Try Catterick - Two caravan dealerships (plus garden centre for a drink) so you can spoil yourselves in the accessories shops
Take the 2nd Catterick exit from the A1 being the A6136. Then you sort of double back on yourself heading towards Catterick. You will find Catterick Caravans approximately 1/2 mile from the junction on the right hand side. Go throigh the lights and the other dealership (Ropers) is just on the right. Turn left at the lights for the Garden centre - a gentle stroll from the caravan places.
------------- If you're not on a fell your wasting your feet and for 2014 it's.......Feb Castleton Mar North Yors Moors; Apr Sutton on Sea; May Thirsk; Jun Clapham/Riverside (Lakes); July Wharfedale; August Crakehall; Sept Knaresborough; Oct Wirral Park/Clitheroe