Hi Murray,
Those propane tanks heaters will need to be able to be run for quite some time. Battery capacity is poor at -40. All I'm saying is that this is not a journey to be taken lightly.
Looks as if I have been misinformed on the diesel.
"In Northern America gas stations offer two types of diesel fuel - according to ASTM D975[5] these are named No.1 and No.2 fuel. No.1 fuel (kerosene) has a natural CFPP of -40 °C but it is more expensive than No.2 fuel. Adding No.1 fuel will lower the CFPP of No.2 fuel - adding 10% will lower the CFPP temperature by about 5 degrees.[6]"
Winter Diesel#2 diesel gels at 8.1 °C
The article goes on to mention Arctic Diesel--which gels at -44 C.