No time should be particularly busy. I scheduled mine in November early for December 19th. 1-2 months ahead notice should be good even if you're in a super busy area.
Also this is just more incentive to take the test once and do well. Instead of taking it multiple times and skimping on prep materials, it is financially better to just get all the stuff you need. And that isn't even getting into the emotional issues of how much it sucks to get a low score, then heartbreak, finally studying again and retaking.