Honestly, this is a question that I've debated. When I finish a draft, I am typically like "that was fun let's not do that again".
I would say, no, you don't have to rewrite it. Heck, especially with parts you really like, you can just transfer over. Yes you'll have to rewrite a lot, but it's your blueprint, your study guide even.
For me, I know I need to rewrite my first seven chapters easily. But I have the blueprints and can "easily" do so.
I would recommend taking a step back and look at the draft. Remember nothing is perfect after the first draft. From first piece of art to first draft of a piece of work - that's why they're called drafts.