Propane torches won't have enough poop to heat up that nut and stud.
If you have a MAPP gas torch or, for sure, an Oxy-Acetylene torch with a wide-ish welding tip or small blowtorch tip, you could certainly heat it up to get it to loosen, but since you've already proven that it's really on there, then there are two tool options: Upgrading to a good-quality 3/4" drive bat handle with a 5' - 6' piece of pipe on it and your enhanced 205 pounds. If your weight on the far end of the pipe (don't bounce it) doesn't get it to loosen up, then heat the snot out of the nut and try again. It will be a good idea to get a bat handle with a lifetime warranty, like Kobalt, Craftsman or Husky. At least if you break it they'll give you a new one.
The other alternative is to drive it on the four studs (it should be fine) to a garage where they have a 600 ft. lb. impact drive and a bodacious air supply (120-160 cu. ft. or more) and get them to remove it, then re-install at 200 ft. lbs so you can get it off when you get home to do the hub swap.
Just goes to show that not all jobs are easy.