Answers on Aging Once Opened
goldenwheels brings up and interesting topic, and here is a short on what I could go on for hours:
Cold: Yes, temperature affects a product.
Sometimes for the good, sometimes the bad. For example, citrus and tropical fruits (raw) are negatively affected by extended periods cold. As for alcohol, wines begin oxidizing once they're opened, and refrigeration can, for a short time, minimize the speed with which oxidation affects wine. Without refrigeration, most wines will show oxidative effects within 24-36 hours, if you know what you're looking for, and be pretty poor drinking 36-72 hours out from opening. Refrigeration isn't always helpful, however, but for those positively aided, I find an opened wine may achieve 2-3 days extra life if refrigerated. And this more for red wine than white.
As for spirits, the same will play out, but over a much longer period whence understanding the major negative oxidative influences have already played out during the distillation and maturation processes. Thus, spirits stay better once opened than wine, apple juice...
A question here is, how long will a bottle of spirits stay drinkable once opened? This depends on the spirit and bottling, of course. In my opinion, most rums keep well for shorter periods due to their often higher sugar contents. Tequilas and many brandies are the next to go. Then Bourbon and Canadian whisky. Then Scotch and finally vodka. There are many reasons for this pecking order which may include the base ingredient(s), the quality of the distiller, mass or handcrafted production, filtration, storage conditions during maturation, storage conditions after production (transport, warehousing, market, consumer's stash).
As an example for Scotch, a mass market whisky like Johnnie Walker, Dewar's, and many standard bottlings of malts like Glenmorangie and Macallan will go through chill filtering and/or a possible color adulteration. These processes, especially the filtering, makes for a much more stable product. They subsequently change less once opened than non-chill filtered whisky because the later have more compounds susceptible to change. Thus, the mass market brands often hold up longer once opened than the more hand crafted bottlings. This greatly depends on the product, however, as many mass produced products are quite poor from the get go.
Crown Royal is a mass produced product and slowing its decline once opened by refrigeration will be minimal compared to what a cool, dark storage cabinet will provide. A benefit of refrigeration, however, for the consumer who might drink it over ice and like it cold, is it is cold and not needing ice when they're ready to drink.
Length of Time Once Opened: I find quality mass market spirits should be consumed within the following time frame before negative oxidative affects start becoming obvious and ultimately problematic.
Light rums 3-12 months; dark rums 6-18 months; tequila blanco 3-9 months; tequila reposado and anejo 6-18 months; brandies 3-12 months; Bourbon and Canadian whisky 12-24 months; Scotch whisky 12-30 months. Vodka is a unique case because it is usually distilled to show next to nothing and is, subsequently, capable of lasting a long time. However, much mass market vodka is garbage and lasts a very short time before off aromas and flavors appear. So, vodka 3-36 months. For hand crafted spirits, knock 6 months off these numbers. For low quality spirits, why bother?
Storage conditions, of course, are important and any particular spirit may survive well outside of this guideline. But don't think the bottle of something you've had open 3-10 years is as good as the same bottling that's only been open a month or two, whether or not it is was refrigerated.
I've had a lot of poor spirits in bars and restaurants. Part of the problem is the more unique bottlings you find out aren't turned very quickly, and they sit on the shelf, back lit, in an environment with continual temperature fluctuation. Thus, I've learned and tend to drink very standard stuff like Macallan, Glenfiddich, Glenlivet and Glenmorangie when out because they're what most people know and are therefore turned pretty frequently. One of the worst spirits I've ever had out (compared to a dram from a freshly opened bottle) is Remy's Louis XIII Cognac; at $150-250 a dram, a place that has it opened has likely had it open 5-10 years and, if so, it will be drink poorly.
I follow a drinking path rather than a storage path, once something is open. After all, a 750 ml bottle is only 1 ounce 25-26 drams, and having a dozen whiskies open at a time means you should be rotating your open stock at least yearly. If you only buy one whisky at a time, you should be through it within two months. If you're not getting through it that fast, I suggest enjoying more frequently and never having to worry about a bottle declining to the point of being poor.
Most consumers don't have this level of experience with being able to identify a poor drinking spirit because of how long it has been open. If they have an old bottle at home, what do they have to compare it to? That said, if understanding this, it can be learned quite quickly. My hope here is, if you ever get a crappy dram out somewhere, you have the knowledge and confidence to send it back - because you're surely going to need to convince the bartender it's off.