I'm confused about this premise? Are you suggesting the Norway debate take place a year earlier, which wouldn't really make historical sense without major butterflies? The Norway debate took place in 1940 and did lead to the fall of the Chamberlain government.
You're confused about what a no confidence motion does. It doesn't mean an automatic general election, it just means that the present government is faced with the choice of resignation or taking its case to the country. If Chamberlain had lost, he would simply have done what happened historically after the Norway debate - resigned.
But does losing a censure motion give him the pretext to go above the heads of his own party grandees (who were pushing him out the door, given how close the vote was) and try to appeal directly to the country? Or is that too desperate, even for Chamberlain?
To what end, even assuming it as a poss? Reduce or imperil the Tory majority, with end result that Chamberlain has to resign anyway. Pointless.
He is still leader of the party - and remained so for months after leaving office. If he's delusional enough to believe he can win, and cavalier enough to risk it, he forces the party to support him.
A general election would see the Tories all over the shop, and no-one is going to thank Chamberlain for reducing the Tory majority to suit his own ends and imperelling party unity. No-one is going to support this prospect.