Richard, that is a broad temp range & hard to decide if dormant or not. I know that plants won't grow if soil temps are around 54 f.
Plants not growing won't drink up much water- if any, so what I do is, put a dry stick (dowel works good) & keep it in pot. Pull it out & feel how much moisture on it to decide whether to water. Or, put a stick in & about 1/2 hour later check it before watering. It won't lie. This is good esp. for big pots where you don't know how wet the bottom is.
EX: I have 2 ICream in 30 gal pots. One is room temp (68-69f) with some south sun & one is in sunroom with temps of 49 - 60f. The one at rm temp shot up 2 leaves since Oct & has been watered 3-4 times & one in S room got no new leaves & watered once. So, watch for growth & good luck
