I never got into options investing, but I believe you keep re-upping them. Every time you do so you pay a small price. So, the game is: 'can you stay liquid long enough for the bubble to pop'.

You can keep a short position for a long time, as long as you can maintain margin, which gets bigger if the stock price continues increasing, and pay margin interest - there is no set date when the short has to he closed, it's indefinite. Sometimes the lender who loaned you the stock can ask for it back, and if you can't locate any more shares to borrow to replace the returned shares, you might be forced to buy the shares back and close the short, but this is not common, at least during normal market conditions.

The longest term seems to be about 2 years.