I can't look at crowd calendars. We typically go down for the busiest times of year, because we are insane. Thanksgiving twice, and this year Christmas. I glanced at the calendar and saw all RED. We survived two crazy but amazing Thanksgivings in the parks, and we'll survive Christmas week as well.
Dining reservations are made, fast-passes have been booked. We will spend Christmas Eve at Magic Kingdom, and Christmas Day at Epcot. We even managed to grab a Candlelight package for Christmas day. It will be crazy packed, but it will be fun, because we love Disney. Just being in the parks is enough for us. We're lucky that the kids love the sights and sounds as well as getting on the rides. If it gets too crazy in the parks, we love resort hopping, and seeing how each decorates for the season.
If I had taken a crowd calendar as gospel when we planned our first trip way back when, I probably would have freaked out and cancelled, and missed out on all the great memories we've made over the years. Just go! Go and enjoy!!!