Oh they'll go on as far as they can. The 1997 election was pretty much on the last day they could hold an election and they were a minority government. Maintaining power is their key political aim. They won't deliberately hold it in winter, so autumn 24 seems very likely.
Christ knows what carnage they can reek in a year. Thank goodness for the checks and balances we have in the UK, to keep these corrupt loons in check. It's a shame we need the courts, commitees and the Lords to restrain their worst excuses.