Hi Jojo, as long as the cork is in good condition and a tight fit then there's no problems about a bottle being opened for a few years, like you mine don't last that long.
If you think about it nearly all whisky companies have stocks of product that may lie in their warehouses for a year or more, it then goes to a wholesaler who again may have it for a year or more, then it reaches the retailer and who knows how long it lies in the shop.
I know of brands that were discontinued 10 to 15 years ago and they are still on sale in shops around the world so unless you only buy new releases how do you know how long its been since it was bottled. The packaging and label very seldom change once the brand is established and most companies now date code the bottles with laser markings that only the company can read.
In the words of the prophet "you pays your money and you takes your chance" that's why I always recommend drinking the whisky rather than storing it.