Apparently the designation varies by country. In some countries Liquified Petroleum Gas includes only propane, but in others it can also include some Butane. It can be a mix of propane and butane.
I only know enough to know I need to read up on this a lot more regarding how it is distributed and sold. I'm not sure but the difference in properties "may" cause supply issues at lower temperatures.
Pure propane has a much higher vapor pressure and is therefore better suited for cold temperatures. According to Wikipedia (I don't always trust everything written there) it's possible than in summer they mix more butane which lowers pressure, and that in winter less, which increases pressure.
I'm not even certain this can happen, but if LPG contains more butane, as ambient temperature drops, system pressure could plummet. And of course it takes additional temperature difference to boil the liquid into gas, so liquid in tank is even colder than ambient when there is a load on system. That's why we wouldn't want to insulate propane tanks.
If you had water or air in system it may have continued to malfunction when you returned to warmer temperature. But since it worked again I suspect the fuel itself "may" have played a part in problem.
The third paragraph in Wikipedia suggest that in North America we use some butane, and that it is altered by season. I'm going to research this more to see if it is true, and also what percentages they use.
https://en.m.wikipedia.org/wiki/Liquefied_petroleum_gas
Although unlikely, it's "possible" the system may work better in cold weather after you refill it next time. May be worth trying if not too inconvenient. By the way, a cheap electric heater can make RV a lot easier to sleep in when there is no other heat source. Don't know how you feel about running generator though.