The thing with DVC is that the resorts book up year round - they sold enough points to book them, and that is what they do (unless people aren't using their points), so it really isn't a matter of how busy it is when you get there, but how fast it books up.
Traditional holiday times book up, but then you get surprises - early December books really quickly - low points and Christmas decorations. Food and Wine is very popular with DVCers. Events like marathons bring in a lot of DVCers. Weird "holidays" like Jersey Week when there are a lot of kids off school at a strange time.
January - once you are past the marathon - doesn't tend to book very quickly. September doesn't. June or August. But by a month out, even these times of year it can be difficult to find consecutive days in the same room type and sometimes people end up moving.
This is one of the reasons that we generally advise people DVC doesn't work great if you can't plan ahead. At eleven months out, you usually get what you want at your home resort. At seven months out, some rooms at some resorts at some popular times of year are already booked - and at six and a half months out - availability tightens further. Four months out and you won't have much choice in resorts for a lot of the year - and a certain times of the year DVC may already be completely booked. Two months out and you have to be very flexible to be happy.