The EU has to agree to an Article 50 extension--the UK can't extend it unilaterally. And there isn't really even time for a general election and a new government by the Article 50 deadline anyway, let alone time to negotiate a new deal. Article 50 can be revoked, but it can't be revoked in bad faith just to unilaterally give yourself an extension before re-invoking it again. And why would the EU grant an extension when Parliament has already turned down the best deal they're going to get?

It's entirely outside of the UK's hands right now. The best option will have to be to let the no deal Brexit happen, allow a binding Irish unification referendum within the next five years, and let the British people learn from their own mistakes.