When I was in the UK 3 years ago I went out with the local paddling club in the small town where I was staying in Yorkshire. Their rivers are mostly narrow and winding, with frequent snags and low hanging trees as well as low angle weirs instead of dams, which they can slide over. Most of the club members use short whitewater boats or 12’ and 13’ solo canoes. (I had a 12’ folding rec kayak which worked pretty well – can’t slide a fabric and rubber boat down a concrete weir ramp but at 24 pounds I just carried it over obstacles.) I certainly would not have wanted a longer boat in those waters.
I keep a tee fitting that converts half of a touring paddle to a single blade for paddling through overhanging greenery (and spider webs!) Did not have it with me on that trip but the travel kayak paddle I had along, a 4-piece carbon Cannon, can have one of the shaft halves removed to shorten it to about 6’ which was what I did during the “tunnel” sections on those British streams.