This is my neck of the woods.
Sutton Bank itself is tarmac (as you already knew) and is great if you want to overtake cars very fast (doing down, not up) :D.
It depends to an extent how far you’d be travelling to get to the area, there are a fair few routes around there if you know where to look, many of them loop round a few key runs so you can get a reasonable ride without ever being more than 3 or 4 miles from your starting point.
There will be a few muddy patches it’s generally not too bad providing you give it time to drain after heavy rains. If you link up between Sutton Bank, White Horse Bank and Boltby Woods there’s some pretty decent riding to be had.