I debated posting this on the Belgium forum, but since my question revolves around Lille I thought this might be the better place for it.
I'm in the beginning stages of planning a short solo trip to Belgium, probably in fall of 2024. The current plan is to fly in and out of Brussels and stay in Ghent for 5 or 6 nights before heading to an airport hotel for 1 night. I plan on day tripping to the usual suspects (Bruges, Antwerp, etc), but one city that is a priority for me that doesn't seem to be that high on other people's lists is Lille. I'm often drawn to mid-size to large cities with interesting architecture, and I like the fact that Lille has a bit of a Flemish vibe despite being in France. I also hope to visit the Palais des Beaux Arts.
I've been to Paris several times so no need to detour there unless it's absolutely necessary, so I guess my question is this: how feasible is a day trip to Lille from Ghent, or would it be worth spending an overnight (or two) in Lille? I normally try to avoid switching hotels if I can make a day trip work logistically. I see there's a Belgian train (with change in Kortrijk) that only takes 74 minutes, with reasonably frequent service. I understand Belgian train tickets are good for any time that day (and I've heard French TER have recently switched to a similar approach -- correct me if I'm wrong), so I'm assuming I could buy all my tickets including return trip right from the station in Ghent on the day of travel? Or would I buy one way in Ghent and then my return trip tickets from the Lille-Flandres station?
Anybody have any experience or tips on visiting Lille as a day trip? The reason I'm thinking about this now is if it makes more sense to stay overnight then I might change my plans to fly into Brussels and out of Paris, but I'd rather not if I can avoid it.