Something sensible you ask?
You may want to look at the current crop of long/ultra long haul flights and see their turnaround times.
Even the single plane TATL 767/757 flights tend to have 2-3 hour T/As.
Bearing in mind all the food and drink, bedding, water for showers and so on..
This type of service of service will require multipe craft on either side to maintain consistancy so the inbound and outbound fligths will be on different crafts.