I thought it was more than one year. Essentially, I thought it was about 20 months (did they not play last year at an alternate site - I thought I saw a game on TV where they were at the other site and this issue was discussed).
Plus, they had a ton of money to throw around to make sure it could get done (money not an object) and didn't have to deal with potential bad weather for the most part (which can impact what can be done at certain times in Kansas).
Not saying it wasn't amazing what was done. It is. And it shows it can be done if you want to make it happen.
A thing like a new Vanier could definitely be done in a year (it would be even easier if lots of stuff was already built in the NW corner (ad even NE) so there is as little trouble as possible impacting the off season (new Weight room, meeting rooms, even a locker room could already be in place). The only issue is the money to make it happen.