Easy: alone, struggling to contact coworkers (while mostly trying to diagnose the problem). I've done both (the alone state didn't last for hours because we did have emergency communication channels, and the hotel was a ski lodge in my case). The surrounded by coworkers is much better.

That's assuming these are actual coworkers, not say a dozen escalating levels of micromanagers, which I agree would be hell. The where isn't really that important in my experience, as long as you've got reliable Internet access.

It wasn't too bad! The annoying bit was that the offsite schedule was delayed for hours for the other ~40 people not working on the issue.