This is one of those subjective things. We all have our own judgement on what is "best" when it comes to taste and smell.
So the "best temperature" is the one that results in you most enjoying your whisky.
Don’t let anyone tell you how to drink it. You bought it so please, drink it your way.
That said, it is generally accepted that whisky should be served at “room temperature” (15 – 18 degrees Celsius).
If you live in a hot climate and need to cool the whisky it is worth noting that extreme cold will dull (or even obliterate) the aroma and flavour.
We reckon finding a cool place to store it (a cellar, a cupboard next to a fridge or freezer or in an air-conditioned room) is better than trying to crash the temperature using ice or stones.
Of course, there are times when we all just want an ice cold whisky and there is nothing wrong with that. On those occasions add the ice in the amount you want. Yes, you will trade off some of the nuances of the spirit but enjoyment is what it is all about.
If you are surrounded by snow and want to warm your whisky to “room temperature” try treating it like a good Cognac and cup the glass in your hand to slowly raise the temperature. Nosing it as it warms allows you to experience the aromas as they are released.