Our Vornado has three settings, 750, 1150, 1500. The lowest setting is enough for temps down into the 40’s. We’ve used the middle setting to get things warm while camping in the 30’s. We rarely use the 1500W setting, in the teens and 20’s it will get the trailer warmed up and then we go to one of the lower settings. It’s got a wide base and is super stable. It also has a switch on the bottom that shuts the unit off if it is not sitting flat.
We’ve been in the Kansas City area the last couple of nights, overnight temps near 40 when we wake up. Using the lowest setting (750) we kept the temperature in the high 60s for sleeping. That’s not running constantly. I think the new ones have a digital temperature readout. Ours just has a knob (8 years old). If you’re not going to camp in sub freezing temps I think the small Vornado would be fine. It’s a very quiet unit. Mike