Re: package is on the way but very cold temps here
Installing a package in below freezing conditions is likely to cause the death of many / all bees. What happens, you dump the bees in, then they have to crawl around and form a cluster. If they successfully form the cluster they will be OK, provided they can be fed. But more likely, large numbers will freeze before they actually make the cluster.
However keeping the package in the package, for more than a week is also likely to result in high mortality.
My suggestion, is less than perfect but perhaps the only option, an indoors install. In say, your garage, heat the whole room to a minimum of 60. Then prepare the TBH so the bees can be dumped in and the hive closed, fast as.
Any bees that don't go in the hive will be lost, so plan carefully have it all ready, queen organised etc, then dump the bees in really really fast and close the hive. A few bees will escape, just accept that but get as many in as fast as you can & close the hive. Have some means to feed them and leave inside for 24 hours.
Preferable they should then be put outside and the hive entrance opened. But the issue is feeding them, they will not generally take syrup at below freezing, so it will really revolve around what method you are going to use to feed them. What are your current plans to feed them?
"Thinking Inside The Box"