There is a definite problem with the cold and the antenna system on the QC.
The antenna system is mechanical, actually moves around looking for satellites and is moving all the time. The unit does not like the cold if it is old or has not been serviced properly (meaning taken apart, cleaned and lubricated).
I have had no signal out in the open on a clear day, I could hear the antenna system struggle trying to locate a satellite.
The other problem is with Qualcom itself, their messaging system is bad; it takes a long time for it to get through their system as a lot of people have said. The message you send does not actually (with most companies) get sent to your company to their computers but stays in the Qualcom computers that act like an email server. An operator at your company sits in front of the screen and connects like they are checking email.