This will be another reason for the traitors to piss and moan.
Just print it yourself. Tons of poster printing services online for cheap. I used PosterBurner last time and it was good. But probably others are fine. Not a promotion. Just what I used.
https://huggingface.co/spaces/gokaygokay/AuraSR-v2
Can use this website to upscale the original image so it's higher resolution.
Huggingface has all the AI photo upscale models so check out others if you don't like the results.
Some others below.
Don't use the "upscale your image for free" sites because they're just garbage ads on top of these open source models.
The poster website will say what minimum resolution they need to print usually. So just scale it until you reach that. Zoom in to the photo though and make sure no weird artifacts appear. They'll be more obvious once printed.
Good luck!