IMO start that baby up and when you have oil pressure it is ok to begin your trip. However, it is not time to drag race. What I mean by beginning your trip is slow even acceleration and keeping the RPM below 2000. Give the transmission and differential time to warm up, too.
Modern lubricants are truly amazing but will not protect your machine if your stupidity is also truly amazing. I do not say this to slight anyone. I just don't feel that long periods of idle are necessary. I feel that the cylinder washdown and oil dilution outweigh the benefits of warm temps as long as the vehicle is driven with consideration for the conditions. I would not begin a trip towing without a few minutes of idle to slightly warm things, but we are talking about pulling a load here. This is not the same as pulling out empty.
Just my losy . 02