I think if he wants to continue playing, he'll have plenty of suitors on a cheap 1-year deal. Key as mentioned, is where he was the "want to" anymore.
He'd probably still draw a bit of attention of bottom-feeder teams with a ton of minutes and opportunity to offer. Where he'd get a shot at top PP time, prime offensive minutes, whatever.
But i'd like to see him go to a more veteran team looking for a cheap "high upside" reclamation project. There'd surely be some of those too.
Colorado makes sense to me. Chance to play with Nate, in a supporting role without a lot of pressure to produce, but a high flying system that might actually help find some productivity.
Pittsburgh is the one that immediately comes to mind though. They're in a really tough spot and could use an infusion of cheap talent. Who knows if it'd work or not, but the chance to potentially play with Crosby/Malkin still seems like an attractive proposition, and it could be the thing he needs to bring out the raw talent that he presumably does still actually have (and has shown flashes of when he's healthy).
Nashville seems like a possibility who could take a chance on skill now that they've moved out expensive Granlund from that sort of role where Drouin might do well.
Carolina seem to take chances on guys and could use some more skill as well. Though i have a hard time envisioning Drouin thriving in that system.
St.Louis would also be a possibility. He'd offer some high-upside/low-downside skill to whatever is going on with their Retool.
Even Minnesota would be interesting if they think he can play Center. With their buyout imposed cap crunch tightening the belt.
But there are probably a few tank teams like Arizona and Chicago that would take a flyer with rosters that need to be filled out with someone.