Great topic. I FIRE'ed 19 months ago, DW is still working until 2021. We LOVE to dine (in or out) and enjoy fine adult beverages as well. For me, what has changed is that I am preparing much more of my own food at home, getting creative and striving to find the really good stuff that isn't really all that hard to make. Also, for things that have a short shelf life, making only 2-3 days worth at a time. I HATE wasting, throwing away food. DW has generally always eaten a bit healthier than I, and goes on and off all kinds of diets, but really is only marginally overweight, and exercises a ton. I don't eat junk often, but cannot imagine life without a Wendy's #2 combo maybe every month or two.
Since retiring, I have taken up walking at least 6 days a week, weather permitting, 1-3 miles, shooting for a 12-14 mi weekly average. Our two dogs LOVE this, and STARE at my every move after lunch every day. We walk/hike in conservation and land trust lands, lots of woods, fields and some ponds to stop and swim in. We go in New England winters no matter how cold, as long as the snow isn't too deep. I have lost 24 lbs since FIRE.
While I always liked cooking, it seemed like it was always low priority, never enough time. But now I LOVE it and DW and I have a really fun weekly tradition. She goes on Friday nights to two back to back aerobics/zumba classes. Usually adds an errand or two on the front end, so I get usually 3 hours, and I prepare a dinner we call "Friday Night Test Kitchen". The idea is that I can't make anything that I have made before. A few days prior, I surf the online grocery store circulars to see what is on sale, and scour the fridge to see what needs to get used up. Then I surf recipes online, usually taking one and twisting it a bit. She comes home around 7:40 and I usually escort her to the seat at the dining table and off we go. I have evolved it to usually start with a "Cocktail Special", again, a drink recipe that I have not made before but might use a favorite spirit of ours. Usually that day earlier, I scour the clearance and sale aisles at the liquor store for a Chardonnay that we have not tried, always looking for a great value-find (any wine lovers use the Vivino app?), but again, can't be anything that we have had before is the rule. Chardonnays because I am a huge fan of grilled seafood and chilled Chardonnay.
It's tons of fun for both of us. She giggles about "FNTK" all week, her friends ask her about it. I do everything that night, including clean up. I have made some killer dishes, and some so-so (is there a recipe thread here somewhere
).
So to the OP's question, I think we have morphed our dining a bit, but not much. We still have a stout dining out budget and do a lot of that as well.
With respect to alcohol intake, about 10 years ago we decided to not drink M-W as a self discipline measure, and we have stuck to it since (vacations and holiday exempt). Interestingly, it has skewed the cooking/diet also, as I refuse to cook grilled seafood on M-W since white wine will be absent.
Lastly, I'll say this, and I am sure other's already FIRE'ed will agree: don't get all bent trying to figure out what it will be/not be. Sure, make some loose plans, have some ideas, but retirement is about finding your "zone" and it takes a little while. We are all different, but you won't know what it is like, and what you will want it to be, until you get there......!