I don't know a lot about this but I have pinched ulnar nerves. I had carpal tunnel both sides too I was told I still have it when had my ENG altho I don't have the symptoms I had before. At times, my hands fall asleep at nite but that is ok. I also have spasms in my arm from the ulnar but never any real pain. I do have hand wasting though. Sure hope pain does not come along.
I would use some hand splints at night. You might also use something to keep your arm straight at night. I bought something at a medical supply store but have not used it. Bending the arm will cause compression esp sleeping on it at night. I was supposed to use elbow pads but they just made me itch. I do lean on my elbows way..... too much.

I also know ulnar nerve surgery is pretty tricky. Did they recommend any PT at all? You might try icing too.???

I don't know if any suggestions are good or helpful but figured would throw in my 2 cents