We have used a propane buddy for heating the tent and it works great. Just burns those little propane tanks (~1 if its on all night) and has a bunch of safety features so it doesn't fall over etc. Our tent always just had air flow to feed it open a crack. Even used it out in the garage a couple times while working on things and it is great.
150$ feels more than what we paid for ours....
https://www.homedepot.ca/product/mr-...RoCEMkQAvD_BwE