Thanks so much everyone.
So the helpful police man who was here this AM has been in touch. I'd given him bank card details and he was able to determine that they were hotel charges in [large port city]--it's funny, the way the electronic payments are set up, we don't know which hotel it actually is, it just reads [city] Hotel Group. The bank says they'll be able to access which hotel it is on Monday.
Anyway, it's clear that Mr. been paying for hotel and food and drink--it doesn't look like someone stole his card or anything like that. So apart from having no heart medication, it seems he's safe.
Here's something funny--I just got off the phone with the police man and he was like, "Actually I think I can narrow it down and find which hotel he's in tonight--and then I'll call you back."
I thanked him and got off the phone, and then I thought: Hold on. Why? My purpose in making a report was just to ensure he wasn't in peril somewhere. Why do I need to know what hotel he's in? I suppose if the police know there's a health risk, they might want to go check on him, that's up to their judgement.
So I need to just let this go. If he's determined to drink himself to death, that's what he'll do.
I'm sick of him acting like a lost lamb, wandering out to edge of a cliff, making us all risk life and limb to save him.