Thanks for the reply. I don't mind the site being full-width at all, but that doesn't have to automatically apply to the text as well. The longer the text lines, the harder it gets to track which line is next, once you're at the end of the current one.
I mean, basically something like
p, li, dd { max-width:800px; }
might already be enough. I shall take a closer look at it on the weekend and post my results here.