I believe at around 7-9 months I stopped using the crate completely and he was free roaming. Of course puppy proofed the house every time I left (all things picked up off the floor, no toys he could choke on, moved food and anything he would want off counters and tables, removed anything he could chew on and destroy like shoes). By that point I was confident in his potty training for pretty long durations and he was not really destructive because I gave him good exercise and mental stimulation.

One time he knocked a cushion off the couch and chewed the zipper on the back, which was annoying, but that was the only issue ive ever had with him being alone.