Well, you don't need a vice - just some means of securing the workpiece. Patrick's shown us some good tricks for that in some of his tutorials, and there are plenty of other options - I did mine with a couple of pegs in my workbench to butt it against and a cable tie to stop it all bouncing around. You could do it in the field with any number of arrangements.
The bow drill is only a couple of sticks and a bit of string (it doesn't need to be able to make fire), sand is easy to find, and the mallet is just the same as a batton. In other words, all the sorts of things you're going to have available in any bushcraft situation.
Improvise and adapt - isn't that the idea?