2016 PSD owner here.
Schaeffer is a fine oil no doubt. So is Valvoline Premium Blue and Rotella. All of those vendors 10w30 are on the list.
I'm in the camp of a 10 w being good to 20 degrees F, so if you get colder than that in Wisconsin, consider a 5w40. Your truck going to a cold climate may have come with a block heater. If so, I would stick with the 10w30 year round. Seriously, you'll find the 6.7 will start and run in any temperature you are brave enough to walk out into unassisted anyway.
I'm running Delo 15w30 in mine, but it gets stored along with the camper from October through March, so no cold starts for me.
Last edited by beanoil; 06/14/18 09:43 AM.