Any TOC that operates loads of stations with limited ticketing facilities, or none at all, is the perfect candidate for a smartcard system. Even one where you merely have a card to prove where/when you touched in - and can still purchase a ticket later on.
So, when a station has no facilities, you merely tap your card to validate entry. And if that machine doesn't work, the TOC would instantly know as all the machines would be connected. This would also be backed up with a vending machine to issue new smartcards to those that don't have one, perhaps for a nominal fee of £1/2 (and refundable if given up at the end of a journey for passengers never intending to travel again on the service).
I am not aware if any such systems exist to merely operate as a sort of glorified permit to travel, but obviously the same system would be able to pre-load tickets or credit for those who don't wish to have to queue up to be sold the right ticket during the journey or at the destination.
You'd still be able to jump on those who try and exit another station without paying, and anyone that magically loses their ticket could get a fixed-rate penalty of £80.
(All of the above requires a lot more than Northern Rail simply imposing its own system.. it will need the DfT and other agencies to get involved, as well as changing rules as necessary to there's a proper, recognised, penalty system not this unofficial one).