As a few data points, the last two days it has been 24F to 26F in my garage when I start the 990S in the morning for my commute, bike is cold-soaked at those temps all night. When I try to start with no "warm-up" to the battery, it spins 3 or 4 times but too slowly/weak to start the bike. I let it sit 15 seconds or so then the second try and the bikes jumps to life, strong cranking from then on. That one start pull on the batt warms it up quick.
A few times in sub-freezing temps I also just turned the key on, let the headlights run while I finished the final fussing with gear, then the starter spun quick. Again, that was a warmup for the battery.
It does illustrate that lithium packs need to pull some current to warm up a bit in below freezing 32F/OC temps. Above freezing the Shorai spins the starter fine.
I have not used a trickle charger or given it a charge since installing.