I think probably Christmas is not a great time.
You make a good point, that it's good for some and not good for others. More lead time would be great. In the future, I'm sure that will be possible, and having done the process once, people know what to expect.
We know, for example, that the Chief Justice will be retiring in 2018. Barring any other early retirements, that gives a certain lead time for people who are interested in being considered for the court to think about it and prepare themselves. The first time is always perhaps a bit more difficult, but you make an interesting point about the courts not sitting. Unfortunately, some of the judges went off to the boonies to their summer cottages, so coming back was a challenge.