I just moved to Evanston from Big Piney. My new to me house has several trees that had been badly neglected and over grown. I don't know what all of them are, but I have some kind of apple, a Canadian choke cherry and several Quakies that I can ID. Two weeks ago the choke cherry got a "hair cut" and last night the quakies met Mr. Chain Saw. All branches below about 6' off the ground are now on the ground. I guess I should have checked on the proper time and method of trimming BEFORE I started but I couldn't stand them any more. I havn't truched the apple tree yet, but I have a few others that are going to get worked on unless someone tells me now is not the time to do it.
I would agree that this would be alright, I do mine in the spring when it warms up however just at the time they are starting to show sighns of waking up. I would suggest not to cut too far back into the tree as to exspose too much flesh but if done you can get a paste that will cover nicely and protect against bugs.