These people were enjoying a proper champagne tasting in one of those expensive bars. The wife and I just had the one glass eachThere last week.
The balloon ride seems worth it in Epernay. 12 euros or 18 euros with glass of champagne. You can see it from miles away. Couldn't do it as wind too high when I wanted to go.
We cycled up and down the Marne canal. Very pleasant.
Hauteville is a couple of km uphill from the canal path with expensive bars but a couple of lovely views. It is also got something to do with Dom Perrignon and it may be the place champagne was invented (or I could be wrong) NB hill to hauteville quite steep for non ebikes
If you want an Aire that is well out of the way and walk 10 yards for stunning views try Mutigny