Ethereum to $100 is not possible, for Ethereum to reach $100 again that means that the market is so bearish to an extent of the fact that bitcoin crashed so much, so don't expect $100 for Ethereum price again
If think that then now ETH is falling and BTC price is increasing, so it is clear that their is no relation between ETH and BTC. Even if ETH price goes to $100 or more low BTC price can increase or decrease but both coin relation is different. Right now everyone is sell altcoin and buying BTC as they expect the bitcoin price to move up in coming days.