I would water them, with the heat on and the fireplace going, they are probably getting pretty dry. I might water a little less, but not much. What are the night temps - the same? Because here in winter I let the house cool off quite a bit (electricity is too expensive) so the heat comes on at 6 am for 20 mins. to get the house up to 68. Then it is off all day and the house drops into the low 60s. Then heat to 68 from 6 pm to 9 pm, then off and drops to low 60s overnight. My 'chids have always survived.