I would take a one-year "sabbatical" from work. We would leave work with no intention of coming back, but would at least try to keep the option open in case we missed work in our year off. We'd travel the world, with a few longer stints in specific places.
A month or two in Niseko, Japan for ski season.
Three months in Australia to surf, enjoy the weather, and enjoy the people.
One month in my hometown, spending lots of time with my parents.
One month in another city where most of my friends and family live now, hanging out with them whenever they're free but otherwise just enjoying the slower pace of life there. It would be a bit of a trial run, to see if we were open to moving there.
The rest would be bucket list trips: Galapagos, Antarctica, Patagonia, Safari in Tanzania, etc.
Do all of our life maintenance tasks between 9AM and 5PM, with lots of time to spare. Hitting the gym five days per week, meditation, groceries, cleaning, laundry all done when the gyms and stores are empty and our friends are at work. Leaving plenty of time for evenings and weekends. Probably get a dog.
At least a few other regular fitness activities (rock climbing, cycling, skateboarding, etc). We'd also build in some regular standing dates. Visiting a new coffee shop in the city every Monday morning, to really appreciate the times when others are at work and we are free. Tuesday date night, take advantage of free activities (movies in the park, etc.)
We'd also take time on M-F, 9-5 to do solitary activities like read books, listen to podcasts, read the Economist, watch TV shows, etc. That leaves every evening and weekend that we'd be free to spend time with friends and family. Not everyone would have as much free time as us, so I'm sure we'd often have to take the lead in making plans, hosting dinner plans, board game nights, throwing parties, planning vacation weekends, organzing groups to go to concerts, etc. We'd also have to devote a lot of effort to making new friends with all of the time we'd have available. I'm sure sometimes we'd be a bit bored or lonely.
There would be occasional longer commitments, I'd like to spend a year training beneath a contractor to learn DIY and renovation skills, something I could use for the rest of my life. I want to hike the Appalachian Trail or the Pacific Crest Trail, and I'd almost certainly start with a few smaller 10-20 day hikes. I've done up to six. I want to attend a long meditation retreat.
Beyond that, just live life. Spend time in nature, slow down and appreciate art (there are so many artists releasing amazing music, I can't keep up). Grow food, cut my own hair, probably start writing a blog, brew beer, make cocktails, spend more time playing guitar and find a group of people to jam with, actually have the time to watch pro sports, get more involved in my local community.
I might even start up a small fee-for-service financial planning firm to help people who are underserved by traditional finance. I've done some work with low income retirees in the past and found that rewarding.