That's fine, but it completely ignores the fact it's all-or-nothing and your odds are significantly reduced. I think you'd be better in the long run to bet 4 games and hit on maybe 2-3 each time than to hit the occasional parlay.
But as all things gambling, Vegas has it all figured out, so I doubt one way is substantially better than the other. Just a matter of preference.
The thing is we are not in vegas. Iowa lines are different. If you look at the wins total for iowa and isu for season in vegas and here they are different