Reims during Christmas

In town, you'll find the same activities as during the rest of the year - but do check closing days for the champagne cellars as I doubt they are open on Christmas day. In addition, there is a large Christmas market right in front of the cathedral (exact dates unknown yet, but last year it stayed open for a few days after Christmas apparently, which is rare for Christmas markets!).

In the region...if you were thinking of visiting the vineyards, perhaps reconsider. Vineyards are dreary when leafless in the winter.

Reims Tourist Office: https://en.reims-tourisme.com. Calendar under What to Do, Live & See tab.

Looks like the Christmas Market is scheduled for 25 Nov - 29 Dec this year.

I spent one night in Reims in 2018 late November. We visited Pommery and Tattingier for their cellar tours and tastings, then spent the rest of the evening at the small but lovely Christmas market. Plenty more champagne to taste there. Other than that, we called it an early night. I should note that I had also been there on a day trip the year before in October, and visited the cathedral and did a guided tour to some of the smaller producers outside of town, so had already done those things. (The cathedral is gorgeous all lit up outside for Christmas.)
We stayed in a cute little hotel with a homemade breakfast near the train station as we had an early train, but it’s not a far walk to the city center at all. We did utilize Uber to take us to Pommery if I recall.

Thanks for the good information. I really appreciate it.