There's no "might be" in the MVF. Did Ultron show he could react to someone as fast as Peter? Because he's like 50x faster than the Avengers version. Ultron will be frozen in time, as he's not faster than a bullet or an explosion and those are slowed to crawls for minutes at a time for Quicksilver.
QS, minus PIS/CIS, EASILY clears this. Only question is how creative he has to get to dismantle Ultron Prime and, if need be, the thruster activation button and the thrusters themselves.
The bots all get scrapped in an instant, and then it's just a matter of time for Ultron. Three most difficult things for Peter to accomplish:
1. Dismantling the thrusters/thruster switch button.
2. Preventing Ultron from escaping into the internet (if this is required, I don't see how he stops Ultron from escaping, but QS can still stop Sokovia from being destroyed and destroying the Earth).
3. Deciding what song to jam out to whilst running at Mach 100k on his Walkman.