1. My btc will disappear so need to keep them in cold wallets.
No btc will not disappear, they will remain in the exchange, the most popular coin will be known as btc rest will be alt coins.
2. Chain will split in 2.
Yes and No, basically to the time the alt is created there will be 1 chain with same data after that we will see 2 different chains with their own transnational data one will be btc and the other will be an alt coin
3. What will happen to the price of btc?
While no one can predict the future, see an example of eth and etc.
