What you describe is kind of what I suspected, in terms of that specific job requiring you to be that available, which is why the question was genuine. I also work remotely, and have at times travelled simultaneously, but never in the same way, unless it's the constraint I'm accepting because I actually don't have the vacation time. As in, if I'm in vacation, laptop stays at home, otherwise I'm just trying to do both and sometimes that's a fair compromise.

Even day to day living stationary, I have a hard time accepting that not being able to escape is a requirement, but I'm not really responsible for any critical systems, and am not paid like that either.