depends on the quality and way it is stored and vintage
the best thing to do is refer to a guide with grading of vintages for advice
No, refrigeration is not necessary.
It was last for decades if unopened.
Paul mason unopened 1852 rare cream
Ruby Port is aged in wood barrels for two years before spending a lengthy time aging in bottles, where it doesn't have contact with any oxygen. This is called aging reductively. And it makes ruby Port very susceptible to oxygenation once opened, meaning it turns faster than a tawny Port which is only wood-aged and has some exposure to oxygen while aging as oxygen seeps into the wood barrels. As a result the ruby Port, once opened for drinking, only lasts about a week.
Chardonnay is good for about 7 years unopened.
If it's a vintage port, meaning it's from a specific year, then yes.
.Who is with you?
Unopened milk can sit out for about two hours before it spoils.
It depends on what sort it is. There are quite a few variables, but it should be good for several years unopened and in a cool, dry storage area. Once you open it, it should last for several months.
3 years.
1 year
About three years.