I use Dvorak on my home computer and any computer I have a chance to use regularly (like my primary office PC). I've remapped capslock to control at home, but not at work.

Typically, the context shift requires no more than 5 minutes, and usually 0 minutes, for me to stop making mistakes. In my experience, the fact that I don't have the precise same physical keyboard helps a ton. My primary office desktop keyboard is different than in the labs (where I have less control), and different than my home laptop. So what I'm typing on feels different and I'm able to quickly adjust.

It takes some practice, I won't lie, but after a few weeks you'll probably not be making any major mistakes.