So, the Wookieepedia article for the Imperial Repulsortank (found in Stay on Target ) cites the old WEG source as being 20.5 meters in length. That's about 67 feet, give or take.
Here's a picture. That's one giant snowtrooper, or something is out of whack. I'm thinking, based on the picture, 20.5 feet in length? Maybe?