Only yesterday I had a brief conversation with the ever helpful Dave from motors and rotors, I had asked him that very question and he did say-not his quote but my recollection, that jetcat have a 2 week holiday/shutdown period, although I am not sure of the date I got the feeling it was very soon.
There after you have to consider the potential backlog.
If the bearing is just a little noisy then monitor it for a change in pitch and return it when you are not going to fly much-that could be the winter? or the summer depending on how you judge the weather.
Winter-cold, calm, sunny, frost, snow,
Summer-wet, windy, drought.
Mark