Well actually I was thinking this myself recently.
However you are correct that there is some technical hurdles to come over.
IIRC the legacy map was about 70GB which is more space than most players have and can run on their internet connection.
Which rules out the large majority however even sharing it between a couple of players would take days.
The best way I can think to do this, if it's decided we would do this, is via a torrent to share the load.
I could put it on my 1GBPs server too to help ease the load a lot and provide 24/7 seeding.
Of course the command blocks and other sensitive things would need to removed but it would be great to see the old base and the ruins of 1.8 such as Pancakia
I also had a little idea for a project of mapping the whole 1.8 in journeymap.