Lee,
I have never towed a caravan up the A537 from Macclesfield but know the road very well.
Not sure if you're familiar with the road, but it is fairly steep in places and has numerous tight corners favoured by motorcyclists. The road is mentioned in many national biking magazines and attracts riders from around the country.
The Cat and Fiddle pub is situated at the peak and is the meeting place for the bikers.
If you do decide to use the road, beware of bikers suddenly overtaking you at high speed.
Martin.