Depends on the part of the world, but in northern/central europe the production of panels from september/october to march is zero, 0, according to my colleague in his roof and many others have said the same. It is cloudy, it will rain a lot and during winter if there are no clouds then there are only.. a limited number of sunglight possible, and the sun is low, so most of the "power" is already absorbed by the atmosphere
This is absolutely not true.
Right now Denmark produces 1724 MW from solar panels even though it is an overcast and rainy day: https://energinet.dk/energisystemet-lige-nu/
Our current usage is relatively high: 5944 MW.
Remaining supply is: 3458 from windmills, 357 from fossils and 434 from import from other countries (mostly hydro/wind).
So if Denmark doubled the amount of windmills (it is a very windy country) and solar panels then Denmark would be able to run of windmills and solar panels even in the autumn.
I'm not sure how far up north you're talking about, but solar production in Stockholm (and I'd argue anywhere north affects so few people that we can completely ignore it for a general discussion) is about 10% of summer production but certainly not 0.
https://profilesolar.com/locations/Sweden/Stockholm/
Stockholm doesn't really have snow that covers the roofs to a degree that matters.
Also, the labor of keeping your roof snow-free is not really worth the savings.