In our part of the world, solar production during winter is incredibly low or 0 due to it being very cloudy, days being much shorter, sunlight angle on the panel very suboptimal. No amount of additional panels will get you through that streak.

It also depends somewhat on how much energy you use. I live in the Netherlands where everytime I bring it up, I'm told "that's just not possible, you will never make enough in winter", but these same people have no idea how much energy I use. On a bad day, I use maybe 10kWh and that's running the AC with the thermostat set to 19c overnight and a bit during the day at 22c. I don't have a giant fridge, I don't have any gaming PCs slurping 200W on standby, etc. My baseline usage is around 300-400W to run the old freezer that never turns off (70W), my network equipment, a fan in the garage to prevent moisture buildup, and some lights.

My 1.8kWh system at 20% output covers a great percentage of my baseline usage during the day! I'm probably going to add a small battery so I'm not penalized for sending energy back to the grid, but I'm not gonna need much until my kids get older and want new gadgets. The cool part about modern electronics is that we're generally getting more efficient too with newer tech. If I replace the old freezer, my baseline usage drops 20%+.

I don't disagree with your point that sometimes nature is simply just working too hard against your efforts, but I also wrote all this to say that some people need to really do the math and not rely on "common knowledge". Energy efficiency has come an extremely long way in the past decade and much of what was true when residential solar first started popping off is now outdated.

I wouldn't say no amount. I think about 100kW of solar would still produce enough for the average house even in the depths of cloudy British winter.

Way too much to fit on a house though.

while that's true, getting close has major benefits. adding extra capacity for the winter also adds capacity for fall and spring. that production will reduce how many weeks the battery is needed for