The idea that you've suggested is a good one - it's relevant to the users search and therefore more persuasive in theory. But what about those users that are flexible on their dates? Or their location? What about the users that want inspiration and don't know where to go?
Do you notice that no other competitor (in the 8 that I've quickly reviewed) does what you've mentioned? It's not because "no one has ever thought about it" - more likely because it's not as strong as the alternative option: a landing page. I would recommend looking at your competition (which from your design see that you've already looked at AirBnb and Tripadvisor!). A quick search will show that most competitors take the user to a dedicated landing page for their sale. That way you can:
- Provide inspiration
- Give users more flexible options around their dates or location
- Promote a dedicated landing page via PPC
You can test your theory by implementing both so long as there is that option almost a "catch all". I'd be interested to see the results. Here are some screenshots from competitors to consider - I'd make your Tripadvisor-esque banner header a large sale banner promoting your landing page - there's a lot of real estate here. The last screenshot below (Sandals) is particularly effective.