Realistically, he's got to get himself elected as a Conservative MP before he can become leader. Competition for safe Tory seats is going to be fierce at the next general election.
Farage isn't an idiot, whatever else he might be, and has, as the post title covers, carefully taljed about after the election.
Montgomerie's comment is about the desire of sone of the Tory members and by having the words 'if they could' acknowledges that they can't currently.