Is it better to leave the truck running or plug it in overnight when it's this cold? My 15W40 isn't moving too well in the AM lately (0W40 synthetic asap for me). Is a cold start up worse than leaving it run all night @ 1250 rpm at these temperatures? Is the DFP going to clog up too much, because there isn't any highway up here where I'm working to unclog it. A limp mode event could be pretty ugly 50k in the bush and 200k from the nearest dealer....