I might not get a chance to experiment with 40°! From what I've read about them in low temperatures, you turn the key on for a minute to cycle the battery, then start it.
Turning on for a minute (with headlight on) warms the battery a bit and thus elevates the available amperage to near normal. They do NOT like to be run down to dead and recharged so do keep that in mind.
Anti gravity battery's? WTF is that? Never had a issue with the stock battery. Working on the second one now at 50,000 miles. Changed out around 30,000 just because. Figured winter was coming and the change was a good idea. Did not want to get stuck somewhere with a dead battery. Harley's and batteries are about every three years. Rocket and stock batteries life span i believe much more. Never had a issue starting the bike even in cold temps. Did have a problem one morning last winter. It was about 10 degrees and could not get the bike to start. Then i remembered that it was in gear and the kick stand was down problem solved.
I swapped out my yuasa for a Duracell equivalent, it's been great so far, but then I noticed the black Friday deal on the antigravity battery, so I thought I'd give it a shot.