Bay area? Go for it. I seen elms at Boons with new leaves already. If you are at the coast as I suspect then it would be good now. I would do it during the repot, and shelter it with these storms we are having. Maybe even a tent to protect from rain and cold for a few weeks. If your getting swollen buds or even signs of green in the buds and you wait you will miss it and have to wait untill mid summer and defoliate and layer then.
I am in the central valley and have noticed the buds here are starting to get round and swollen. About two more weeks or less if we get some sun after this week long storm. Prior to the storm I had a few days over 60 degrees which is the key temp for moving sap and waking up.