My 2011 Cadillac warms up pretty quick so no need to wait on it, just start and go. My 2004 Dodge Cummins 2500 PU is another story. Since diesel engines don’t build up heat like a gas engine it takes me about 10-15 miles of driving at freeway speeds before I can turn the heater on unless I let it warm up in the driveway for 30 minutes. Last week when we had single digit temps it was brutal leaving work heading home.
Leave the diesel running. I have an “02” Ford with 326k on it and I almost never turn it off. 14 hrs uses maybe 5 gals of fuel.