starting equiment that ic cold from being shipped

Um:

I would open them up and let them acclimate for 3+ days (mainly because of moisture).

DeKay

I too am in the upper Midwest and just yesterday received new electronics from Hattor. They were on the truck 3 extra days due to the snow slowing delivery. They were cold when I unpacked them so I let them reach room temperature over 5-6 hours - no condensation (I checked inside) and no problems.  Of course waiting longer will not hurt.

Tubes yes you should wait a bit so everything warms up some so the temperature change isn’t as drastic.

SS, probably won’t make any difference.

All the best.

If it were me? 24 hours. Keeping equipment wrapped would make evaporation take longer and increases risk 

Some water is going to condense inside the amp as it warms up

Water + amplifier = bad

Need time to everything to come to ambient temperature and for condensation to fully evaporate

It sucks, but better to wait than to fry the amp on your first turn-on

Hair dryer