For the Yukon Territory leg of your trip on the Alaska Highway, The Yukon Amateur Radio Association has an excellent system of linked 2m repeaters that also includes the road south to Skagway, AK. Details & map here. http://yara.ca/repeaters/repeaters.htm
The BC Public Service Net is indeed held at 0130z (6:30pm summer time) on 3729 kHz. The most northerly Net Control Station is the one in Quesnel that covers Tuesday nights.
You should be aware that BC highways have little cellphone coverage even in the populated south (it's not quite an election issue, but the incumbent government mentioned upcoming improvements in their pre-election feel-good ads!), and in northern BC there is almost no cellular service at all. For coverage maps, if you're an AT&T or T-Mobile customer, the major GSM provider is Rogers; if Sprint or Verizon, the major CDMA provider is Telus. I have been told by truckers that nobody listens to CB up there anymore, trucks all use commercial frequencies around 155 MHz FM. But in the summer the Alaska Highway is busy enough, you won't have to wait long before you have a chance to flag someone down.
Nelson VE7NAE (ex-VE8NE/VY1)