I heard the following on the Community mailing list: There is another repository which (as far as I understand the matter) is:

1. the same as the OCA/vertical_hotel
2. is ready ported to v8
3. there is only missing a "pull request" (at least that was the term I remember) to be made from https://github.com/JayVora-SerpentCS/hotelmgmt_v8 to the OCA repository

What I didin't understand was why that had been separeately developed and why no one made the pull request so far (I guess do to lack of urgency for the person who could do that (because he probably is just happy with his own repo))

To me this was no very urgent, so I deciede to wait it out. If I am not mistaken you could either try to make the pull request happen or use the https://github.com/JayVora-SerpentCS/hotelmgmt_v8 repository

I didn't go very into depth with it, so the above is more a hint on where to dig deeper then a confirmed set of instructions. If you gather any news on this maybe you can add them to this post.... hope this helps somewhat