The usual way of training for cycling in winter is to get a stationary bicycle. It seems neater, somehow, to use the same bicycle for both outdoor and indoor biking. You can buy a stand that holds a bike’s rear axle and applies a variable amount of pressure. It’s a little harder on the seat of the pants, because the bike doesn’t sway and change pressure points. However, we got a second one and so far I’ve had two short sessions side-by-side with my SO: about 40 minutes yesterday and about 20 minutes tonight. It’s not bad so far–I have the pressure on the tire very light. It might make the spring jump onto the bike a little more successful.