if your temp is in that range i would say you're alright for the time being.
you don't want the tank getting too cold, or too hot, but if it is staying in the goldilocks zone itself, you should be fine.
from what i understand you can cycle at cooler temperatures, but it will retard the growth rate of the bacteria. i'm not sure what the absolute lower bound is, but if you're staying within the normal parameters for reef tank tank temperatures, i would say you're fine.