Totally depends on where you camp and what you do to manage the temps. If you are connected to shore power, you have many options. We have a three bunk model so lots of tenting. We are almost always connected to shore power.
Heating - we've been below freezing and are easily able to keep the main part of the trailer in the 70s. We use an electric space heater for primary, and the propane furnace as backup or secondary. Reason for this is that the propane will go fast and, most importantly, will generate moisture in the trailer. The bunks still get a bit drafty and quite a bit cooler. We use PUG covers over the tented ends and that helps both condensation and temp retention a bunch. Finally we leave the tented windows open a crack to keep fresh air flowing and that minimizes condensation as well.
Cooling - If you want to keep the main part of the trailer in the 70's you will have to be connected to shore power. We've been in 100+ temps and at best we keep the main trailer peaking at about 78-80F. We have to close the curtains at the bunks so the heat pouring in tends to stay there. But the rest of the trailer (roof, walls, single pane windows etc) all contribute to the trailer heating up over time. If the nights cool down well, then it should be manageable.
Overall, it's still quite an improvement over a tent :)