One of the things that surprisingly we do not see much speculation about is when the next general election will be held. Whenever people talk about the date they tend to assume that it will be in 2024 but looking at what previous Prime Ministers with big majorities have done the timing tends to be no more than 4 years after the previous one.
Boris Johnson or whoever is Tory leader effectively has it in their gift to choose a time for the next contest which they consider to be most beneficial to their party and there is always a risk of hanging on until the final year possible.
A good moment is to have the party conference at the start of October next year and call the election the following week
Those old enough to remember the late 1970s will recall how the LAB PM, Jim Callaghan, was accused of making a massive mistake not holding the election in October 1978. The same thing happened with Gordon Brown in 2009 when all the planning had been for an October 2008 election. Indeed a huge amount of money had been spent by the party on an election in the autumn of that year and Brown’s dithering over the date put an end to his polling honeymoon.
My guess is that Johnson or whoever succeeds him will only be too aware of the precedents and won’t risk hanging on until the last possible date. The current odds on 2023 look attractive.