if eth price rises, is there a chance crowdsale is already over?
I don't think so. Every project aims to sell his tokens offered for sale irrespective of the price. So even if eth prices go up or go down crowdsale token share(% of token supply offered to crowd) would be the same.
Most project I did encounter doesn't really rely on ETH price on reaching out their cap. As avirunes said they do aim for the tokens sold even the price of ETH surges up and hit up the cap most likely they wont really stop as long the coins not being sold completely as just being stated on their crowdsale.