I might give this a go. I'm more comfortable with Max from prototyping layouts and placeholder models during my dayjob already, so this seems like a great excuse. I do agree that the timeline does seem a bit daunting.
I'm sure many people will say they could ship a map by the date you've suggested (might not look or run great though, depending on the person), but I personally worry about the necessary buffer time allotment for playtesting and iteration, custom asset creation (start to finish), and optimization.