I don't think the election will be canceled for two reasons, or maybe two and a half.
First, I don't think Trump's ego will allow for him to plan for something like this. He is literally incapable of imagining a scenario in which he's not beloved by everyone, so the idea that he could actually be voted out is just not something he can comprehend very well. This makes planning for such an event difficult.
Second, assuming I'm wrong about this (or that Trump is manipulated into affecting the election), it's too overt. It would cause significant unrest, even more than we've already seen. Even if Trump's supporters among the powerful don't actually care, it's still messy and would hurt their bottom lines. Especially when there's an alternative: create just enough in terms of impediments to voting and the like that the election still happens, Trump wins, but there's nothing overtly illegitimate about the process. If it takes more than a single sentence to explain why the election is illegitimate, you've lost the argument. Meanwhile, Biden will concede "for the good of the country," and there we go. It's rocky, but Trump gets what he wants, and without even more civil unrest (read: economic harm).
The third / second-and-a-half thing is that, like uhsguy says, there's not the support among people who could actually pull this kind of thing off subtlety. Trump has his acting DHS secretary, but I question whether enough people within the DHS and other three-letter agencies would actually be willing to go along with this for it to work. At that point he'd have to do something incredibly overt, which brings us back to my first two objections, only worse, because he'd have significant parts of the defense/intelligence establishment openly opposing him.