It seems quite likely to me the a Johnson PM would force a no-deal through then immediately call a general election. My expectation is that on the morning after a no-deal the ordinary person will attempt to go about their job exactly as they did before, unless somebody tells them otherwise, and this will carry on until some part or drug or rule from on high stops them. Stockpiling will delay this point (but Christmas is a complication if the October date holds.) So it could be a month or two before no-deal really bites.

So the Tory pitch would be:

a) we have delivered Brexit
b) the claims it will all collapse have proven unfounded
c) we need a majority to deliver everything in the manifesto.

That could be a winning path, as it weakens Farage a lot and the fears of the remainers seem unfounded. But the longer it is delayed, the greater the risks, as no-deal Brexit is more like a house of cards - it can stand successfully for a while, but if it falls, it could do quite dramatically. Wait until the legal limit for an election and that could have happened. Do it early enough after a no-deal and you will get away with it.