I have a variety of thermometers setup in the RV (bunkhouse, queen bed, dining, and thermostat) and there are wide variations in the temperature especially when it gets cold outside. There are even differences between the thermostat on the wall and the thermometer above the dinette. The bunkhouse is always the coldest even though I checked the heater ducting located under the fridge and all the connections look fine. Keep in mind, too, there is a draft to the outside kitchen from the bunkhouse if you haven't blocked off the TV with the plexiglass mod. That's one of my modding plans for the future.
I found that the digital thermostat needed to be set several degrees higher than normal (i.e. 72 or 74 instead of 68), to make it feel more comfortable inside. I discovered this was because the thermostat would not actually turn on until the temp dropped a few degrees or so below the set temp. I believe it is designed that way, so that the heater is not constantly cycling on and off at the slightest change in temp--which could be quite annoying. Although, the variance that garysol experienced does seem wider than you'd normally expect.
I don't think the Premier is insulated enough for cold weather and the internal temperature drops quite quickly. Last winter, we basically used up an entire 20 lb. propane tank every weekend.
This year I bought a couple of portable electric heaters from Walmart. The
smaller Lasko one is only 200w and is perfect for in the bathroom.
The
other Sunbeam one is 1000w or 1500w and when setup on the floor between the sofa and the dinette, heats the entire RV very, very warmly--even the bunkhouse. I keep the curtains open a few inches to allow for air flow.
BTW, the Walmart online prices seem to be a lot expensive when I purchased the heaters in-store earlier at the end of summer. They were only $10 and $13, respectively. Now, we never need to use propane for heat which should save us a lot of money this winter!