The inventor was not enamoured enough with the limited functionally of contemporary jeeps. They are practically indestructible. With the commonwealth connection they could have been ordered by the RCMP or army.
Whatever the hell Fraser drives up north it's probably something with horsepower and torque. Definitely not the speed and manoeuvrability of a normal city/domestic vehicle.
Fraser's preferred areas are, at least I read as, very isolated, extreme and sparsely populated. If you crash or your engine fails and you can't make an immediate repair, there's nobody coming for you, nobody knows your location and if you're lost in the conditions then nobody sane is going to follow you into whatever mess you're in, you can't get your vehicle recovered or repaired... unless you get very lucky with a c b radio [and they don't work so good as you get closer to the pole], outside town just enough, somebody may come and get you, or you're going to be giving a very long goodbye.
If the motor's still working, you can possibly buy yourself some time, but sooner or later hypothermia is still going to get you so, basically, you're fighting the inevitable.
Safe driving is the difference between life and death. There is no backup: there is nobody to help you, there is nobody coming for you [or at least not unless you're close and the weather is relatively clement] and no way to fix your car [unless it is something immediately repairable] if the motor stops and goes cold you will not be able to restart it, nowhere to fuel up [so even if you can keep the motor going for heat, you can't last out long]
Effectively, you are dead already. You're going to run out of fuel before anyone comes looking for you, so you'll be frozen dead. So safe driving can save your life.
If you're Fraser and think like Fraser, you might have, say, some skis and a sledge in the back... and/or know what the fuck you're doing, you might be in with a [tiny] chance.