Mine go kind of feral in the winter. Our riding is outside only so usually we find ourselves limited to maybe one or two days a month...if were lucky. They will be more tense, physically rather than mentally. The frozen ground is hard for them to maneuver on, makes for rough rides. They tend to always be agreeable, mentally.
Basically, we clean, put food in stalls and open barn doors and gates. They see themselves into the barn and correct stall...well, correct stall most of the time. No halters or lead ropes.
By the end of winter, we sort of have to halter break and teach them to lead all over again. It takes a couple of days..they're good boys.
My Arabian was an absolute nutter during the winter in his younger years. The last couple of years he has been pretty chill year round but until he turned 10, he was like the energizer bunny on crack from October to May.