I agree that $900k isn't the goal we should focus on, but it's still a nice milestone for people to be aware of. It feels very reachable right now, which is a good thing.
Regardless of the extension though, if we hit $900k with 3 days to go, that'd be amazing. That's only $100k away from the million, and seriously, once we break that million, things could get nuts super fast. There's no doubt in my mind that the last third of the funding could be crushed in even a day, if people realized we were that close to getting funded. Even some pessimistic sideliners might throw in, just to say they were a part of the "miracle."
It's important that the campaign attracts enough newcomers on its way to the million though, so that we wouldn't need to stretch ourselves too thin to make that last push. It's way more doable than a lot of people think, they just gotta believe! (and have it in their budget, of course)