I don't know that there have been any circumstances this year where I would be prevented from running an election, or maybe at the outset of the outbreak when there was more confusion amongst the population.
In your scenario, if I recommend to the Governor in Council to cancel the writ, it is the decision of the Governor in Council. They must, by law, call a new election for those districts within three months. Technically, then, the scenario can be repeated if it's not better in three months.
That is the absolute worst-case scenario in the books.