Perhaps George Osborne as somewhat younger or maybe Boris Johnson as he is from London which swung quite heavily against the Tories or even Zac Goldsmith. A real big catch would be Ruth Davidson who is very popular in Scotland, but not sure if popularity in Scotland translates into England as Gordon Brown gained in Scotland but lost in England.
I don't think the Tories losing the next election is a foregone conclusion for a few reasons.
1. With the re-distribution the boundaries should be slightly more favourable to the Tories although only 5-10 seats.
2. Labour needs 64 extra seats to win a majority and that means winning ones they lost by over 10 points as well as probably some where the Tories got over 50%.
3. Jeremy Corbyn is quite left wing so no matter how unpopular the Tories become he will have a much tougher time than Tony Blair did in pulling away soft Tories
4. While I know many don't trust Tony Blair, I saw a recent interview with him and he wasn't sure the coalition Corbyn won can stick. The industrial north voted heavily leave and if Corbyn endorses staying in the single market which means free mobility of labour (EU has been clear UK cannot remain in the single market without allowing free mobility of labour) much of that could swing over to UKIP. By contrast his big gains amongst college educated, London, and university towns were people who oppose Brexit so not demanding Britain stay in the single market could cause them to go over to the Liberal Democrats and if the Liberal Democrat gains come all from Labour the Tories can then fall below 40% and still win a majority.
5. The Tories assumed it was obvious to everyone he was too left wing so never properly attacked his fiscal policies, while next time around will go a lot harder after them.
6. A lot of Labour voters were protest votes who wanted to punish the Tories, but weren't ready to hand the keys of 10 Downing Street to Corbyn but since no one thought he stood a chance at winning, many safely assumed they could vote Labour to punish the Tories without them actually winning. Now that there is a realistic chance of them winning people will think twice about voting for them.
That being said I still think Corbyn could very well win the next election, but it is not a foregone conclusion and with the decline of third parties I don't think a landslide for either side Like 1983 for the Tories or 1997 for Labour is realistic. You need third parties to do better for this to happen as it seems both parties pretty much have a ceiling around 45%.
So I think the Tories like anyone who has been in power has their issues, but they are not in as bad a shape as they were under Tony Blair or Labour was in the 80s. And if you want to talk about Conservative parties in bad shape in the English speaking world, that would go to Canada without question where the Tories at least federally do face major problems whereas the British Tories I don't think are yet at the stage but depending on how Brexit goes that could change. Never mind they are in much better shape than the GOP was in 2008 or Liberal Party of Australia in 2007 and yet both bounced back fairly quickly.