It's really dependent on the personality of the puppy, if you're willing to sacrifice some household items in the event that the dog isn't ready, and reality.
What I did was set up a time on my offday.....letft skype and webcam on so I could watch the process "away from home"...and left him for several hours alone. But, could come home immediately if things weren't going well... However that might not be an option for you.
You could always just try things out and experiment. My one dog reached his full adult status (personality) by 8 months. The other one I couldn't trust until she was over a year old.
Provided your dog doesn't have anxiety issues or is hyperactive there really isn't a lot to worry about. However, anxiety can lead to costly destruction damage....