If there is no demand then the price will go to 0$ but as mentioned above, that's unrealistic and impossible to happen.
Exactly bitcoin remain because there is a demand, but if there is no demand then it will results to a drop of its price until it reaches 0$ but I think that wont happen. Why did I say? Simply because bitcoin was just now in a devoloping and growing part of it. Bitcoin gives more profit and changes ones life. It is very useful now so I think people wont stop buying it.