Cold air intake would make trivial difference at most. It pulls air from the same place so the only thing it would do is reduce restriction due to rough edges on the intake tube. The throttle body is a bit of a bottleneck. It may also be worth looking into a new intake manifold. I'll be putting a new intake manifold and headers on mine with the 383. Current engine has a bit of piston slap during warm up, so I'm not adding a ton of power to this block.
MPFI may help with the cold start issue you have, it doesn't get much colder than 20* here in Dallas and even then it's rare, so not much experience with real cold weather here, but it always starts up within a second of engaging the starter.
I do have a slight issue with idle that just started, wonder if anybody could weigh in on it. Occasionally after startup the idle will cycle between 500 and 800rpm. It's intermittent, but I've tested vacuum and fuel pressure all good. I did recently replace my exhaust, manifold back (new flowmaster cats, magnaflow side exit cat-back). New O2 sensors as well. Reset all bolts to spec after having it installed for a month. Does a new set of cats and/or O2 sensors require the ECM to be reset?
Sent from my SM-G965U using Tapatalk