First off, you are doing great - it seems you have adapted to an OMAD lifestyle very well, and have seen some results :D I love how you look at hours fasted per month - never thought about it quite this way …
The important thing, IMO, is that you maintain a positive mindset - perhaps this cold season you’ll “only” be able to do 18:6 or 20:4 - that’s still awesome and amazing, and as long as you make sensible choices about what you eat - e.g. bone broths, chili con carne but without carbs …. who cares if you eat for another 2 or 3 hours/day - this is not a contest … its a way of living and you need to roll with the punches, not be stubborn and get clocked. The only person that will see you in the mirror is YOU.
I live in a far more temperate area, but do OMAD (23:1) just like you with occasional 48 hr fasts, but if there was some really important social event (e.g. kid’s birthday) and my window that day was 3 or 4 hours and I had some cake and/or pizza, I’m 100% fine with that - this is a marathon that never ends, so I figure if 98% of the time I am living clean (leaving \~7 “poor” days a year), that’s not what will change the overall trajectory. I actually lose appetite in (my) cold weather (which would be like mid to late fall in the Midwest), so your issue isn’t one I have, but we all have our unique circumstances and need to figure out a way forward.