Is it the bolt threads or the internal threads on the tractor?
If it's the bolt you can take it to a machine shop and have them weld it and rethread it.
If it's the threads on the tractor the only option is a thread insert or helicoil which is going to be tough since it's so far to the threads from the bottom of the tractor.
Bobcat Toolcat 5610G, Deere X744, Cub Cadet IH 982
The neighbor was working on a old Deere and had to pull the crankshaft because it had a knock. After the work was done, they found out the oil filter bolt was over tightened and damaged the oil pump which probably caused the knock. It sounded like it was a major job fixing the pump too.
Is the filter cover loose or is it stuck to the gasket holding it in place? It may not be stripped, it could just be stuck.
Over time those gaskets get hard as a rock and can be a bear to get the cover off.