A lot depends on how well balanced the flywheel is on your particular Kickr. I have had several Kickr Snaps and some of them literally shook the entire house. Wahoo support was great at helping get me one that had minimal vibration and didn’t emit odd noises from the bearings.
When I ride early, the kid is sleeping right next door. I built an isolation platform using washing machine dampers and plywood. That sits on a rubber mat, and that’s on a carpeted floor. So far, I’m not waking anyone up.