Although they are not happy to operate below 63 o F this is good enough, as constant temperature is more important than a lower temperature that fluctuate.
As all AC units have to get rid of condensate it is a good idea to let the condensate drain on the floor if it is covered with stone gravel, this will keep the humidity relatively high.
If it is too much the condensate could be drained into a bucket that can be empty when needed.
One word of warning, and I have learned this the hard way.
Most wines age rather than mature.
Wine today are made to drink relatively early.
If expensive top class French wines are the reason for your new cellar then it is worth while, otherwise, beware.
Serge