The period between the Thanksgiving and Christmas breaks is one of the best times to go. Your travel dates have the advantage of seeing the Christmas layout without the Christmas crowds. Definitely spend some time at Grinchmas.
We go the first weekend that Grinchmas starts. We normally go Thursday-Sunday. The only day that is busy is Saturday normally.
The last time we went the weather was good on Thursday temp around 65 and sunny. Friday-Sunday is was 35-50 with rain. We made the best of it but still had fun. This was the first year that we had bad weather. Normally the weather is very nice during the day and cool at night.
You should have a good time with light crowds, enjoy.