They didn't? Sure, they fell off a cliff, but into water, and, as the writer of this article points out, the post credits scene showed Bedelia with her leg being served to her at a table set for three. Will and Hannibal survived.
Honestly I don't think Hannibal needs to turn into a remake of SOTL and I don't think the show suffered at all from the absence of Clarice. The most interesting part of Hannibal and the main focus of it was always the relationship between Will and Hannibal. If you want to remake SOTL then remake SOTL, but if you're going to continue Hannibal, then keep it as its own separate thing, continuing to be vastly different from the novels. Make it stay about Will and Hannibal and their dark romance. Almost everyone who was invested in the show was invested because of their relationship. Making the main focus of the show about anything other than those two would be a huge mistake.