This would be a funny fight actually. The sheer difference in skill, experience, hand speed, and of course the size difference would make for a very crazy clash. Like if a 50 year old Michael jordan played 1v1 with a 7 foot 240 pound high school player on PEDs. Sure Jordan would have an insanely huge advantage in experience and skill, but...would it matter? Thats the million dollar question. The fury fight taught us 1 thing: never count out wilder's punching power. As long as the final bell hasnt rung, there could be a knockout or at the very least a knock down. Its entirely possible wilder loses literally every minute of every round due to his sloppiness and impatience, then lands a bomb out of nowhere with 2 seconds remaining. Or a other possibility, it becomes an incredibly ugly mud fight with both men unable to gain a clear advantage. It would make Baer vs Carnera look like poetry in comparison. Floyd's skill and hand speed would be offset by his tiny size and weak chin. Wilders height and devastating power offset by his horrible accuracy and skill. It could actually take a long time for anything signifcant to land for either man.
I think it'd take maybe into the mid to later rounds to happen. Szpilka doesn't have the best chin, and isn't as skilled as Patterson, yet got to the 9th. But yeah Wilder probably catches Patterson coming in a some point and gets the stoppage.