This is normal winter range! In chemistry the rate of a reaction depends on time and temperature. Your lithium hydride is obeying that law. One trick you can try and the Chevy bolt that I have has a timing system that conditions the battery, warming it up to room temperature 69 or 70° f. Use that system before unplugging your Bolt. It will warm up the cabin as well as the battery. It takes about 20 minutes after which you can unplug it shut off the heater in the cabin and you will see the range jump up about 20%.
Once the car has had its battery warmed up initially it will continue for your entire trip. It did for me and my spouse when the outside temperature was 31° below zero occasionally you might need to turn the fan on if the Windows start to fog up but that's just for a few minutes and it will return to the original range
