Looking for the most epic bike trail in the red zone. ( One that can be used in December )

In the middle of December, with my friend we will be travelling through this red zone to our friend in Portugal. We both ride all kinds of bikes and motorbikes and we’d like to do some kind of fun. Preferably with rental bikes since we cannot bring our own. I’ve been looking online but it would be awesome to have suggestions from local legends. It can be downhill, mtb, fully e-bike. Any ideas?

Thank you!!! ❤️