The difficulties of painting too close to winter are:
Because paint takes longer to dry in colder weather, a longer time between rain showers is needed and you often cannot get more than a few hours of dry weather, accurately predicted.
Some days you may find yourself at nightfall needing to shut doors and windows on paint that is still wet.
Wood has a greater moisture content in colder weather and new painting will seal in this moisture, risking paint bubbles when the sun does come out.
You can try to overcome these problems by getting an accurate weather forecast and with an early start, finishing with the actual painting a good few hours before nightfall thus giving enough time for it to dry.
But you do need luck and if you’ve employed decorators they may find themselves compromising with best practice in an effort to get in a reasonable day’s production.
I’ve done outside painting in winter myself, when younger and it’s hard on morale, arriving first thing in the morning to find the windows wet from a cold, damp night and having to spend extra time drying them out somehow and then, lo and behold, it rains again.
So although your home may suffer a bit of winter exposure because the paint is flaking here and there, it might be better overall to leave the job until early spring.