Mike and Donna are a super friendly couple, genuinely interested in their guests and fully of knowledge of the area, and really warm and inviting.
For a local-flavor dinner, they suggested the Te Anau Dairy, which had good fish and chips, and a wide array of chinese dishes. They make everything to order and it seems like the whole town eats there; it took them 50 minutes to make my meal. So, pro-tip, call ahead to order, and then just swing by to pick it up.
The room was new, clean and spacious enough for me as a solo traveller. It's part of what's a little like a hostel of two rooms attached to their home, so it's really separate, and they share a big common area with a kitchen, laundry facilities, and sitting area. They keep costs low by not charging a cleaning fee, so this area I cleaned up after myself (this isn't always the case at AirBNBs, so worth noting, but easy to do).
When I was there there was nobody in the other room, but I would have welcomed it, as I suspect it'd be a great way to meet other travelers.
The only issue I had was that the room was cold. There's no permanent heat in the bedroom, but there is a radiant heater. The problem was that the radiant heater also is a really bright light, so I couldn't sleep with it on, so had to turn it off. I was actually woken up by how cold I was. This is a simple fix for Donna and Mike with a heater that isn't also a light, and maybe a thicker blanket or duvet.
Overall, this is a great place to launch your fiordland adventure. They're friendly folks and I'd recommend a two-night stay to get to see the area more, and to get to interact with them more.