Never seen grub worms around here sadly.
My scale does down to ounces and to the decimal point. It's ones of the most sensitive scales out there lol :) I've used it for guinea piggies (the one who was supposed to be 5 pounds and was 1.6)
He even snubbed his favorites which shocked me. Then he decided he was tired of me trying to give him food and wander off

lol.
Not sure on temp, I ordered an under-the-tank heat pad (for a third of the tank I think) for the night since I don't think those night bulbs are any good. Used them before and he was always sleeping during the day (more lazy, less likely to eat).
I read that during brumation they usually don't bask in the light as much or at all? He does
Another note, before I gave him a bath he was doing a "swallowing" motion which I noticed when looking down on him.