I want to propose a radical idea: you do not have to wait until you are in your 60s and retired to become a snowbird.
Why should you winter in warmer climes? There is no snow to shovel or slush to slosh through. The skies are brighter and there are fewer grey days. The sunshine is energizing. You do not have to keep track of mittens.
I understand many people have jobs and families that keep them from spreading their wings and flying south as soon as the weather turns cold. But if you hate the winter, find a way to escape it--for a weekend, a week (or several), even month(s).
If you work for yourself, what's tethering you to home? Can you work remotely from a friend's guest bedroom in Miami? Do a home swap with someone in San Diego? Convince a client in Tucson to fly you down for a week or two of consulting and workshops?
Academics: get a grant! Find an archive in the sunbelt and apply for travel funds. Cancel lectures for a week in February and make your students do fifteen-minute meetings with you on Google Hangouts to discuss papers. Head to the airport and spend seven days replenishing your stores of Vitamin D.
Have a desk job and kids in school? Play hooky. Take off a Friday and a Monday and find a non-stop flight to somewhere warm. It doesn't have to be an expensive destination; you can skip the beach resorts and touristy places. Book an AirBnB in a residential neighborhood and spend your days playing outside in the yard or at local parks. Do what you would do if you were staycationing at home in summer.
My point is: retirement is wasted on the old. Travel now, while you have your health and resilience. Who knows if our generation will even be able to afford to retire? Might as well invest that money in your mental health--maybe it will prevent you from impulsively quitting your job in a fit of late-February pique.