Sharne,
How do you intend to cross to the other side of England to get to North Yorkshire?
A route i have used a few times when travelling from Somerset to Chatsworth C.C. site( Derbyshire), North Yorkshire being a bit further up the M1 or A1, is M5,M42-M1.
You could then stop at Wythall Caravan Club site just off the M42.
This would be approx half way for you.
It is an easy tow as it is motorway and dual carriageway virtually all the way.
Tewkesbury Caravan Cub site is very close to the M5 but would leave you a longer second leg of the journey to North Yorkshire.
Hamer