Triple towing is not legal in any of the east coast states along the ocean (don't know about the Idaho totes)........ You do see it some ....... Like anything else some get caught some don't.........I do know in Virginia the trooper will make you disconnect the second trailer & leave it behind.....
I could drive with no or expired tags for months & not get caught or get caught the day they ran out.......... Just a matter if you want to follow the law or not and take the chance.......
There is a web site with the different laws for towing in each state.