Effectiveness of Dehumid. with low temps and a ventilation fan on?

Hey gang
Humidity getting high, gets to about 69 when the lights are outsometimes. I bought a 50 pint dehumidifer and I'm ready to put it in the room only a few questions. I have a 6 inch Vortex in there as well, and I'm curious if the d/h will help with that much ventilation constantly taking place. Also curious on the d/h it says it won't work properly if the d/h is in a room under 65 degrees because frost will get on the coils. My room and entire house gets below 65 degrees sometimes (heat is too expensive!) Anyone have experiences with this?