A thousand times this.
There is a "How it should have ended" video where one of the four possible suggested strategies made a LOT of sense. They suggested that right after Thanos shows up and Dr. Strange says "Oh yeah... you're MUCH more of a Thanos", he could have basically used his cloak to pull up Thanos' arm, dropped him through a portal and then snapped it shut as his arm was passing through, severing the arm with the Gauntlet. Same as what happened to Thanos' minion on Earth.
Sure, in reality it would have been a LOT harder to coordinate, but cmon... it's Super Heroes. Seems as likely as anything else that would have been done.