I took a similar path with my personal site. I did get to the point though where I didn't want to duplicate things like my site banner across all my pages, so I ended up writing a very barebones site generator[0] for compiling handlebars templates.
I prefer scripts to do monkey job for me instead of templates. They take html as input and produce html as output. It's trivial text processing. But this way every text pattern, even that I would have never thought of beforehand, may become a 'template' in the future.
[0] https://github.com/anderspitman/assg