Hi Barry, Is there a reason why you need to repot it now, that couldn't wait till later when you know its positively the right time.
This isn't really directed at you Barry, but it brings a good point up. That people try to rush things. If it isn't time, then it isn't time. No matter what it is, potting, pruning, wiring. The art of growing a bonsai is in the timing and the patience it takes to wait for that time. I am beginning to believe that the one attribute of a master or really skilled person that makes them great (above all else), is that they have learned to be patient. As with anyone that has learned to do something extremely well....they wait for the moment and then they strike. I find it almost humorous that people who pursue bonsai as a eastern discipline vs. a western style. Are setting the Japanese as a standard, yet they don't want to display the patience that the Japanese have demonstrated in their masterpieces. I believe in being aggressive and look for opportunities to achieve results, I also know when to pull the reins back.
Like I said Barry this isn't directed at you, it just a statement I hear on a daily basis or read on the forums to much. I just wanted to give my 2 cents worth.
My suggestion ( not knowing your micro climate) is look at the trees around you. What are they telling you. Are the buds swelling on them as well? Google your past weather history for your area, does it indicate that you'll continue having mild temps. or historically does it still stay pretty chilly. The answers are all around you, just take a look and do a little research.