My camera shutter jammed during a dawn shoot on a cold ridge. Debate time: field fixes or wait for the bench?

I was up on Granite Peak last week, aiming to get some early light shots with my old SLR. The temperature dropped overnight, and when I went to take a photo, the shutter just stuck. I had my basic screwdrivers and lens cloth in my bag. On one hand, I've heard repairers say that a timely tweak can save a shoot and stop worse issues. On the other hand, I've also seen cameras ruined by well-meaning but hasty repairs in the field. I decided to pack it up and fix it back in my shop, but I missed some great shots. What do you all think? Is it worth trying a fix on the spot, or should you always wait for a controlled space?