I ride all year too. As @Coaster2 mentioned, before the snow hits, when temperatures are about -3 and below, we get “hero dirt”, where normally soft and muddy ground turns grippy solid, and you can be a hero because you can ride terrain that is normally unrideable. After the snow hits, the riding can get great too, because all the nooks, crannies, rocks, and roots get filled in with snow, and you can get some of the flowiest riding of the year. Trail and conditions choice gets a little more tricky, depending on whether your on fat tires or skinny, studded or non-studded, how deep and how well packed the snow is. Ice can be very dangerous without studded tires. The bike can go down like lightning, too fast to get a foot down.
Of course, you have to dress for the conditions, but it’s generally easier to stay comfortable in winter than it is on hot summer days. Just pile on more layers. Often, though I start a ride with more than I need. To about -1 I can get away with shorts and shin pads. Until about -8 I can get away with a long sleeve jersey with a windbreaking layer. Below that, I need to add a fleece. Hands and feet are the hardest for me to keep warm. After about 20 minutes of riding, I generally generate enough heat in my hands that they’re comfortable, but until then below about -3, my hands hurt, even with winter riding gloves. I bought heated grips, which I got a good deal on, which work great. Before the heated grips, I would bring hot pack hand warmers inside my gloves to get me through the first half hour of a ride. For the last couple of seasons, I’ve been using winter cycling boots, which have done well to keep my feet warm.