Not much to add to the comprehensive notes of the late Mr Tallis (presumably kindly taking time off from gigging with the shades of Mr Palestrina and Mr Lassus - that’s a supergroup I’d pay good money to hear), and I would endorse his view of not being scared to drive around quite a bit. There are clearly marked Routes Touristique du Champagne (and local area maps are readily available from shops and hotels) which take you through some very pretty flower-bedecked villages (with evocative names for the Champagne lover!) and some fine scenery. I don’t know Mr Tallis’s Dom Corbon, but a favorite house of ours in Cramant is Voirin-Jumel ; lovely wine, lovely people.
We did the Pommery tour a few years back and it is very well done, comprehensive, and culminates in a tasting, so that’s all boxes ticked - to the extent that we didn’t feel the need for any further “educational” visits, and just went straight for the tastings thereafter! (Incidentally, Pommery have an extensive modern art collection scattered throughout the winery and cellars, some of which is more than a bit bizarre. )
We have also stayed at A. Bergere on the Avenue de Champagne in Epernay, and regularly call back to stock up on their excellent wines - I believe they are much better known in the Low Countries, and don’t really market in the UK. I have to recommend our favorite restaurant in the region for your Epernay stay - La Grillade Gourmande - about ten minutes’ walk from your hotel. (Well, maybe 10 mins there, 15 mins back…) Trust me, the restaurant is much better than the website!
Another regular call of ours (we go to the region pretty much every other year) is to the wine shop Au36 in Hautvillers, just north of Epernay. They have a good range of grower champagnes you would struggle to fine elsewhere, and some well-structured tastings (in English if required) including a comparative tasting of the different champagne grapes which is a real eye-opener. For the Grandes Marques and more celebrated houses there is no shortage of shops/warehouses in central Reims or Epernay.
Finally, to recommend one book/guide to take, I’d avoid Richard Juhlin’s doorstopper; we much prefer Tyson Stelzer’s guide and try to ingore it is written by an Aussie.
I hope you have a grand time - do report back!