For the past few years I have used an 18,000 btu indoor rated propane heater. Even though it is indoor rated it still has some fumes which I have grown less tolerant to over the years. I want to replace it with an electric heater but only have 120v outlets in my garage. The largest heater I can find for 120v is 1500 watt or roughly 5,000 btu, in a 2 car garage I doubt this would even make a dent. I understand that the best solution would be to run a dedicated 220v outlet to run the heater off of but we are actively looking for a new house and I would prefer not run new electrical if I don't have to (and my house panel is out of spaces so I'm not sure if I can bring a single line from the meter panel of if I would have to run a sub panel). My next thought would be the laundry room shares a wall with the garage, how bad of an idea would it be to run a 220v extension cord from the dryer connection to power a heater in the garage? I'm not trying to keep the garage at 70+ degrees, just need enough heat to get the garage to 50-60 degrees in the winter. Any thoughts?