There is a hotel right at the airport. Just literally two minutes walk. It is between the domestic and international terminal. This would be a nice place to go and have a nice dinner while you wait.

We get to the airport about 3.00 pm. To get through the check in and immigration process could easily take 2 hours so you would need to really allow 2 to 3 hours by the time you reclaim your luggage from storage if you need to do that first.

So arriving at 3.00 pm and leaving by 7.00pm to 8.00pm having to be back at the airport by 4.00pm to 5.00 pm to be safe does not leave much time for a tour. Then you could get caught in traffic. .

If anyone is travelling business with anyone travelling coach most lounges allow one guest per passenger. That may be a better option.

Just my two cents worth I think you need to think about that before committing to a tour.