No party would change their leader if that triggered a GE they weren't 100% certain of winning. Self interest will come first, on either side of the house.
And given the choice between a couple more years of Johnson and the current situation I'd take the latter every day of the week.
Truss saying, correctly, that she's not the slickest communicator is a bit of an own goal though. Media and credibility with other leaders is a huge part of the job. Maybe too much, but that's the world we live in. Why Brown was out of his depth despite a greater sincerity of purpose than Blair. Similar for May and also a big part of the reason why Miliband was unelectable.