I definitely suffer from it. It is like a switch goes off in my head.
I was sitting out in my back yard one day which had very variable weather conditions. Sun shining brightly (I feel great, must get out on bike, do shopping, tackle some of those jobs...); thick black clouds blow in, blocking the sunlight (woe is me, the bike can stay where it is, I bet that it will rain and catch me out if I walked to the shops, I can't be arsed with jobs today...). The clouds blow away and the sun reappears (I feel great, must get out on bike, do shopping, tackle some of those jobs...)!!
These days I just get into a winter routine and pretty much ignore the outside world and weather as much as possible. I am a retired grumpy old singleton though, so I can get away with that. Obviously, anybody who has to interact with other people can't do it.
I have considered getting a passport again and spending my winters on the Costa Blanca. I have watched a few videos recently of pro cycling teams training and racing there and they reminded me how much better the climate there is. I would need to start earning again though to be able to afford it.
The thing is, even with the turbo trainer I only average about 10 hours a week moving around. I average around 158 hours a week on my sofa or in bed! Without the turbo I would be sedentary for nearer 163/168 of the week in bad weather and counting the days to a heart attack or some other serious health condition! (Also, even though I am only staring at computer graphics on a big screen, at least I am virtually cycling round nice looking sunny mountains and coastal roads.)