See the link I've attached for more information regarding gasoline breaking down. The gas we have today is not the same stuff we had 20 years ago. With ethanol blends all over the place now, it just doesn't store like it used to.
Obviously, how it's stored can have a lot to do with that. If you store gas in a plastic can that's completely full and sealed air tight, it will keep for quite a while. If it's not completely air tight then it's not going to last as long. If the container is not full it will last even less time. There are fuel conditioners (like Sta-Bil) that can be added to the fuel that help prevent the fuel from breaking down.
There is also differences in fuel systems that come into play. Some carburetors are not as sensitive as others. The carburetor on your snow blower engine is one that just doesn't deal well with contaminated gas.
For what it's worth, the carburetor problems from deteriorating fuel we see on this engine brand are seen on other branded machines that use the same engine. Not to mention all of the "big 3" small engine brands (Kawasaki, Kohler, and Briggs) all deal with these issues as well.
The situation is just extremely variable with the fuel. In winter time, many places use gas that has more ethanol in it than what's used in the summer. Some places have more a humid winter time than in summer. Temperatures are different. All these things come into play on this. Mainly the ethanol causes the most problems. Ethanol causes an awful lot of problems with small engines. Small engine manufacturers are working with fuel makers and congress to try and figure other options in regards to new fuel standards because it's causing so many problems.
Because of all this, I do recommend using a fuel conditioner (like Sta-Bil) to help maintain the gas if it's not going to be used pretty soon.