People really should have learnt by now that going 'oh I'm going to pick a random figure out of the air for what this party *needs* to win four years out' is not smart. Reform's strength is that if politics fragments they may be able to win with a third to a quarter of the vote, yes.
But their weakness is that two-thirds of the electorate really don't like them. (This was *not* true of Margaret Thatcher in the 1980s - most SDP/Alliance voters chose her in forced choice polling). So a more effective government than the one we currently have should beat them.
Well, I hope you're right and I admit it's 3+ years and Farage has a fantastic inability to share the limelight but at this point I feel pessimistic. As in 'your last sentence' pessimistic.