It took me some time to figure out if there was accommodation opportunity in windhoek airport or nearby. I finally found Etango Ranch Guest Farm. It's the perfect solution. They have pick-ups from/to the airport. The ranch is beautiful, the rooms clean and comfortable. I thought dinner was rather expensive (20 euros per person) but they had just opened the restaurant and maybe they'll need time to figure out right menus for reasonable prices.
The place is efficiently managed and owner and manager were both caring and very helpful.