Found a puppy on the side of the highway, so now I’m trapped in my house, I guess

I found a 6 month – 1 year old ish puppy on the side of the highway in rural missouri. The shelter's full so I'm taking care of it for a couple weeks. I leave him on my deck when I'm away and overnight, so he doesn't piss and shit all over my house. I know your not supposed to leave a puppy alone for more than a couple hours, but I need to make money presumably so I dont starve and die. How long can I realistically leave him alone for on my deck. It takes me an hour to drive into town for context. Am I just fucked?

Edit: The shelter is aware of how ill-equipped I am

Supplys: bowls, doghouse from previous owner

I have a friendly neighbor, but I can’t expect that much from him. He’s not a babysitter