we 100s of mile of xc and single track riding.
There’s 100s of miles of singletrack and XC in the New Forest, if you know where to look.
Unfortunately none of it is legally rideable due to the byelaws.
I would think Moors Valley is your best bet if you have a couple of hours to kill. But can get busy on weekends. As suggested, parking charges can be easily avoided by parking nearby and riding in.
Was up at Ringwood forest recently. Quite shocked by what they had done. Looks like they are turning it all back to bog/marsh. Although I’m sure in time, trails will be re-established.