The 120 has proven to be fairly spectacular on range. I'm not sure how big the tank is but I'm sure it's quite a bit less than 2 gallons, and we've been able to get somewhere between 60-75 miles out of it. Of course that's a GIANT range of uncertainty, and that's because none of our bikes have a speedometer or odometer or anything, so I'm not really sure how big the distance is. But I picked out two points that I consider to be the bare edge of the 120's capability, and Google Maps says that by pavement and gravel it would be 39 miles one-way (the 120 can do the run two-ways). I don't know how much shorter or longer our dirt-roads-that-no-one-has-taken-since-WWII route is, but on the map I'd say it looks substantially shorter. I can't remember whether we used the Gatorade bottle trick on that run, but it seems likely. However, it should also be noted that dad's 100 Yamaha ran out of gas, and the 120 had to donate two beer cans worth of gas to keep the Yamaha going, so that would almost kind of cancel out a tiny bit of it.
So yeah, 60-75 miles, with a top speed dictated by short gears to be 45mph or so at ~10K revs. The 250 Husky will most assuredly not get that much range from its 2.1G tank.
And with regards to the Gatorade bottle trick, it should be stressed that the bottles are emptied into the tank as soon as the tank has room for it, to minimize the "gas = scary" factor. On the riding we do, the "good riding" is an unfortunately long distance from camp, so oftentimes you've got the gas in-tank before anything heavy happens.