So the other day I was running about 65mph on the highway and out of nowhere the truck lurched into "limp mode" or something.. I thought I had run out of gas.

I couldn't get it to accelerate. I had to feather foot the gas just to get it to the next exit and pull over. It idled just fine so I realized it is not an issue with the motor. However, I still had to limp it down to the bar (don't judge) where I was meeting some people. Later that night it seemed to run better. I have since driven it several days without any issue.

What could have caused that kind of foul-up randomly on the road?

What should I check to make sure it doesn't happen again as I am driving it 400+ miles round trip for birthday weekend.

 

Check your wiring. Battery cables and all your grounds. This is a fairly common issue when the transmission computer isn't getting a full 12 volts.