We were 5 people who stayed at Karen's place 4 nights (2 adults and 3 kids, we checked in advance that it's okay with her). Karen was very kind and responsive and the location is very good, but we had no internet connection during our whole stay (I had to work really needed it). Karen said that there was some technical problem and very kindly invited me to use the wifi in her house (but it felt kind of weird for me…).
The place is simply too small for 5 people, and I'm not sure that being 4 would have made a difference. As one of the other commentators wrote, it's a small basement suited best for 2 or maybe 3.