This one happened to me on the two ferries and a bottle of rum tour a few years back. About ten k’s before Opononi one of my throttle cables broke right at the twist grip nipple. It was dark so I carried on to the pub (I run a separate cable to each carb on my 71 Bonnie so still had one lung running) where we all spent a most enjoyable musical evening – but that’s another story in itself. Next morning we made temporary repairs by cutting the plastic off on of those electrical connector blocks, see photo. As the other cable was knackered and only hanging on by a thread both were replaced.
Probably wouldn’t be strong enough for a clutch or brake cable but it lasted the rest of the trip around the Bay of Islands and got me home to Papamoa.