There are (as of February this year) three Howard Johnson restaurants left. One in Maine (Bangor) and two in New York (Lake Placid and Lake George).
The fourth to last was in Waturbury, Connecticut, and was forced to change it's name
earlier this year.
According to that article, the company that own the rights to the name for restaurants (no longer related to the hotels) is looking to relaunch the chain. The article doesn't make it clear if those remaining three will be forced out first or not.