With ljh05's basically perfect Eric fight of around 16 seconds (starting after the cutscene and ending when they get a point), the only improvements possible are either new routes or better movement. It seems 43-50 seconds is the average time to get the jerry can and the average time to reach the crates in the garage is about 1:00-1:15~. With all of this, I think sub-1:20 is not possible with the current route. I would love to be proven wrong though!

me personally ive had faster overall runs i was able to place the jerry down at 48-55 secs but overall flop a 1:20 to a bad fight. Fastest ive experienced is a 1:05 fight that flopped due to bad RNG. Therefore i believe that sub 1:20 is possible.