Late grafting

I have two M111 apple rootstocks that I didn’t get grafted. They are leafed out. I do still have dormant scion wood in the refrigerator.  Should I graft now or is there not much chance of success? I could pot them up and wait for next  year.  Maybe I should graft them close to the top so if it doesn’t work, I can try again next year?

You could try bud grafting since that is often done when the trees are actively growing. Also, if it doesn't work out, only a small portion of the tree is impacted.