So A1 print size is 23.4 × 33.1 inches. You're probably not going to look at it much closer than 3 feet away. Take a section of your image that you're going to have printed, re-size it to 180 ppi and print out an 8.5x11. Hang it on the wall and back up 3 feet and see if you can see anything you don't like.
Honestly it will probably be fine, but you don't know until you print it out and take a look at it.
Pixel-peepers will always notice something wrong. Don't try to please them.
Let me know how it looks. I'll be curious to see what you think.