Hi Mynameuk!
Of course, nobody wants to expose their best bike to the worse weather. That's especially so, if they only have one great bike. However, with two bikes, usually the older bike gets assigned all of the winter duties, while the newer bicycle gets taken out of storage, somewhere around Spring time.
So yes, by all means...Hang on to your older bicycle for all of the less than pleasant environmental challenges, that mother nature has in store for you. Your older bicycle has many more days of service that it can serve you. Just be thankful that you are fortunate enough to have two bicycles, instead of only one.
Happy Trails....
- Slim