I ride year-round. I also did so when I had external gears and chains. Of course, I usually bought aluminium bikes for that reason, but my latest (and probably last) is a titanium jobby - unfortunately with a steel fork. I may swap it out at a later date for some custom titanium thing.
Maintain the chain and gears (oil the chain and wash off road salt), and you should be good to go for years and years. Truth be told, I rarely washed any of my bikes, and rarely oiled the chain unless I felt it needed it (too much noise) and things still kept on rocking. You can get stainless chains these days. They're worth it.