I do maintain some level of vim knowledge for when I'm on strange systems. But it's not hard to install my emacs config so if I'm going to spend significant time on a system I will do that.

But if you can ssh in, you could just tramp on your local emacs to edit files remotely. It's quite magical.

In my case, I have to support a large number (500 or so) Linux boxes that are hosted at customer sites (for a custom middleware-type application). And the remote access they have provided for us isn't a direct ssh connection, it goes through a web based gateway using an old active-x control, and embedded shockwave/flash based app (yes, yuck). I'm in the process of replacing that now.

How does infrastructure like that ever happen? Reading that made me feel slightly ill.

I just use tramp to edit files remotely in emacs. Works reasonable well.