Weald of Kent is my old neck of the woods, lots of paths and bridleways, we used to either go north to Croakham HIll/Park, great loop on the Greensand Way and Limpsfield Chart, then up to North Downs along The Ridge near Woldingham, you’re in Surrey then mind, you can follow the NDW all the way to Box Hill and Ranmore if you have the legs. We would also ride a bit further south at Abbots Wood near Hailsham and Friston Forest near Seaford, great old school XC if you’re after a change of scene. It’s so frustrating about Ashdown, been chucked off before even getting the bike out the car, must have someone on permenant look out.
Edit – someone mentioned Rotherfield, but I’ve not been, might be worth a venture.