I remember something that would blow it up and then print on 8.5 x 11 paper that you would then tape together.
Off subject for a moment, but I think Office Depot sells a service where you bring your image in on a thumb drive and they’ll make a poster of it for you.
Back on subject I’ll see if I can come up with the one I’m thinking about.
This looks to be the process I was thinking of.
https://smallbusiness.chron.com/print-poster-printer-57226.html