I added some images and additional comments to my post just above your most recent.
Yes, late winter. Your tree is no jeopardy of becoming something that you cant fix or is harder to fix if you wait until you're ready to repot or for the better timing offered by doing the work closer to its spring push. The only issue you have now is in the fact that when your tree lays over, the branches will still want in what would be their normal orientation relative to the horizon or vertically. That's a minor issue if you're not trying to create a showpiece, and could be avoided entirely if, for now, you simply tip the pot so the trunk is oriented vertically and fix the pot in that position. That way, when you DO move the trunk to a vertical position, the branches will be where they would have been had the trunk been oriented vertically all along.
Al
