I have different needs in my dotfiles for different contexts, so I've created a system where each file is represented by a folder, which contains separate file snippets for each context.

So in my vimrc folder, I've got a work file, a school file, a home file, and a base file (which applies everywhere). Then I have a bash script that stitches all the relevant chunks together into a cohesive file for a given location. It can even do sub-locations by adding underscores to the name. E.g. 'work_nas' will produce a file consisting of the base, work and work_nas files, concatenated together.

This all sits in a private git repo, and I just manually copy the output files to wherever they belong whenever there's an update to them. I've been thinking for a while about writing a script to copy them into place, but GNU stow looks pretty interesting.