Found this in the new garden (moved in v recently). They appear to have been lightly pruned of late but don't look in the best health. Best tips on how to bring this back would be greatly appreciated
I'd plant it then leave it alone til spring
Yes. That pot is far too small and it's probably starving now. Plant it in the ground and let its roots grow as they should. Make sure you give the root ball a thorough soaking first and then again after planting.