I live in northeastern PA and it does indeed get cold here. I'm not much of a cold weather rider and generally don't venture out when the temp gets below freezing. In my case, the loss doesn't really affect my rides.
Battery performance does indeed drop off in cold weather. Storing & charging your battery indoors is always a good idea. The cover I mentioned isn't neoprene but it does contain a good deal of fiber filler which will provide some insulation. The performance loss you see will depend on the length of your commute and whether or not you can store & charge the battery at work.
There have been quite a few posts here on cold weather battery performance. You might want to check these out:
https://electricbikereview.com/forums/threads/cold-weather-battery-best-practices.30229/#post-224575
Hi guys! The subject of keeping Lithium-ion batteries insulated has come up from time to time, because cold temperatures impact how capacity is expressed and this impacts range for electric bike riders. I've got a couple of solutions to share, along with some history, but let's begin with a...
electricbikereview.com
What is the temperature where you will not use your ebike because the temperature is too low or will damage your battery? I charge my battery indoor, but I keep my bicycle outside because I don't or can't hall my ebike upstairs three stories daily. I commute with my ebike 3-4 times a week. My...
electricbikereview.com