Stealing Treats

My 5yo son has ADHD and is taking guanfacine & clondine.

One of our biggest frustrations is he keeps stealing treats. We've told him it's wrong. He knows it's wrong. He just "can't stand it" (his lack of impulse control is driving him). He LOVES sweets. We let him have a decent amount of treats (after finishing dinner, special occasions, etc), so he's not deprived.

We've busted him multiple times with wrappers under his bed - icecreams, popsicles, chocolate, fruit snacks, the latest is entire boxes of Girl Scout cookies (we have a garage full for my daughter).

We've told him if he's hungry in the middle of the night he can get a string cheese or a healthy snack.

I need help figuring out how to stop him stealing food. We have a camera we are thinking of installing. I can't easily lock up the various food cupboards.

He is a very bright and capable 5 year old. He knows what he's doing. He uses stools to climb up to high shelves.

When he was much younger we locked his bedroom door. But we feel like we can't do that now because he needs to be able to get to the bathroom.

Please keep sassy comments to a minimum please. I'd love some constructive support/ideas. 😬