It's a great bike for the price. For what it's worth, I've done plenty of loaded touring in mountains with similar gear ratios (compact crank with 11-28t cassette). Others will say your lowest gear ratio (1.2) isn't low enough for mountainous touring. Depends on your strength and how much you're carrying.

To get it lower, you can buy an 11-34t cassette which will bring you down to a 1.0 ratio.

However, I'm not sure the derailleur it comes with will fit an 11-34t cassette. If it doesn't, you'll need a mountain bike rear derailleur like this.

In short, you're looking at $30 or $70 to upgrade to a traditional low touring gear ratio, not including labor.