It is technically possible. I would tell you, though, that what you would lose is your ability to frame the throne speech in the same way, because it would have been impossible to have the consultations in that way, in my view.
Once I was the project manager for what I think was a pretty good Speech from the Throne for the Conservative government, so I have some experience in this. It would have been challenging to have such a short one. You would probably have had to keep it within the PMO, which wasn't what was done in this case. There was widespread consultation and framing of future directions with the public service.
Just to make sure I'm understood accurately, it is possible that it could have been in one day—and I answered your question honestly and accurately—but there are some advantages to having a month's time or so.