I have found that Poland during the day with overcast conditions looks like there's a severe storm approaching. I actually quite like the mood, it's also overall darker as a result. However I haven't had any issues where I'd say it was too dark, and actually all the provided screen shots look good to me on my monitor with normal brightness settings, granted it's not HDR so I don't know what it actually looks like in HDR, but you say the issue is with HDR turned off anyway. I feel the screen shots look pretty realistic for the conditions based on the way the sky looks. I quite like it.
Only time there were I found areas that were too dark was when the game initial launched, some areas of New Zealand were broken but that was patched up nicely. Haven't had any complaints about it since. But I would light the headlights to work properly in more conditions, as the tunnel in Monte Carlo is blackness. Headlights do work effectively during Overcast conditions in Poland though, I use them often.