if your coil packs are rooted, you wont be firing on 1 or more cylinders which will make it sound like a rex.
but also, as you mentioned it was cold outside, the intake air would have been denser than usual so you would've been running more power (obviously before it cut out) which explains the +2psi in boost as well as the car blowing out the spark at the plugs with a .8 gap.
if it was a 1 off thing then id blame it on the air temps. if its continuous then i'd be looking at replacing a coil pack, cas or gapping your spark plugs to .65.
i'd be doing the cheaper thing first.