If you’re vaccinated (and better yet, boosted) and considered low-risk for severe covid infection, staying in a house/vacation rental with family members who are also vaccinated and low risk is not much concern to health experts. Risks go up if you’re considered high risk, or someone else in the household is vulnerable (elderly un-boosted family members, unvaccinated kids). Risks go way up if people in the house are not vaccinated.
For hotels, the real risks are what you mentioned: busy lobbies, gym, crowded elevators — not the air between rooms. Mask up in public places, maintain social distance if you can and practice good hand hygiene along the way.
Natalie B. Compton