This is our favorite show. Sometimes we see it a couple of times in one day! I dont think you will need to worry about any of the show times during January. I could be wrong but I've always felt as though they have seated everyone that wanted to come in the theatre. Just get there about 10-15 minutes ahead of time and when the theatre opens just sit where you prefer. Are you worried about getting in the front row or something? If you want your child to participate then the first couple of rows would be important but I think it is a better view from further back. And of course you don't know whether your child will be chosen to dance regardless of if you are sitting down front.
We have seen this show so many times that my husband recognized one of the retired Tumble Monkeys working in another totally different job in WDW this year. He has an amazing memory for faces. We LOVE this show. Enjoy!!!