Two ways to go. Block heater or interior heater. Block heater helps with starting and you get heat faster from the truck. they range from 400W to 1200W depending on what ya have. takes 20-60 min to install. When my diesel was my daily driver and I only had 8 miles to go to work it was the way to go. I had mine on a timer so it came on at 3AM and warmed for two hours.
You will not like your bill if you leave it on all night. The interior heater just blows warm air and does nothing for the heater but it does make the interior toasty for the short trip. Here again it needs to be on a timer.
Have not tried my block heater in my 06 GP because it has a remote start.but it did have one from the mfg.(rare option) I may start trying it out with the timer just to see how it acts. Some thoughts.