Ambient casting temperature

[Martini2]

Just seeking opinions on if cooler is better room temp while casting.
This past week I ran 20+# of alloy in short time by alternately filling two 45 cal. molds. They were Lyman 457125 and 457132 molds at 530 & 535 grains. After initial fills to warm molds they started casting "keepers" and pace seemed much faster than summer. The outside or in this case garage temperature was 25-30 degrees F. For this run the pot temp was right at 800 F. & a digital proportional controller and thermocouple are employed in pot. Also employed is a very small fan to air cool the sprew plate. I'm looking forward to casting about 80# more worth of greasers to feed the hungry smoke poles this summer. How low can casting operating area temp be. The size and cast weight of these pills are par with these molds. This seems logical any one's experience vary? Best for holidays, RobertB