In Cambridge there's a lovely crawl to be had between 4 pubs where the longest walk is perhaps 15 minutes and the total distance is a leisurely two miles.

however, 17/18 is colchester weekend rather than Cambridge if you want a beer fest. Nevertheless, I'm quite sure that nearer the time something can be found that will meet requirements.

Heck, if you want, york is do-able. which is a town you simply have to visit (still functioning viking drainage systems - like the paris catacombs but without the graffiti)

keep to the Fen Causeway