I would buy an oil filled electric heater. They are not instant on or off…they warm up slowly and slowly cool off. They tend to be easier on the electrical bill and are a smaller fire risk. We use one in our camper at the beginning and end of a season with 2 dogs.
Kismile 1500W Oil-Filled Radiator Heater, Oil Heater with 3 Heat Settings, Heater with Adjustable Thermostat, Overheat & Tip-Over Protection, Portable Safety Features for Home Office (Grey) https://www.amazon.com/dp/B08G4VBRC2/ref=cm_sw_r_awdo_navT_a_0A6S2TDHGBXGCQ32Z5ME