Champagne-Ardenne TGV is a high-speed rail station, not an airport, sitting just outside Reims on the line between Paris and Strasbourg, so the honest question here is really about a trip built around Reims and the wider Champagne region. Yes, travel insurance is worth carrying for that kind of trip, and the reason has more to do with rural driving and cost-of-disruption than any unusual danger - France is a well-developed destination, but a policy still earns its keep the moment a connection or a rental car plan goes wrong.
Reims has its own university hospital and handles serious cases without the referral chain some more remote entries in this guide require, so the medical picture here is genuinely reassuring for most visitors passing through this part of northern France. What still matters is checking whether your existing health cover extends abroad and specifically to France, since EU residents and visitors from further afield face very different rules, and this page cannot know which applies to you.
Most visitors are here for Reims Cathedral and the Champagne houses, with many building in a drive along the Route Touristique du Champagne through the vineyards - narrow rural roads, tasting stops, and September's grape harvest bringing heavy agricultural traffic that slows travel and raises the odds of a minor accident. Confirm your policy covers self-drive touring and rental-car excess if a vineyard-route drive is part of the plan, since a package rail trip and a self-drive vineyard extension are not always covered by the same default terms.
Keep any clinic paperwork, police reports for a road incident, and receipts for treatment or vehicle recovery, since claims involving a rental car need clear documentation of both the incident and the repair or recovery cost. Many policies also require prompt notice before non-emergency treatment is arranged, so check the claims process in your policy wording before setting out on the champagne route, ideally before the trip rather than mid-itinerary.