Backpacking - travelling with 'smart' clothes

Attach a dedicated bag for your suit (flat packed of course) to the outside of your backpack? Seems like the only good way to do it, tbh, outside of having it couriered between places you need it.

Surprisingly, according to other business travellers, the answer - yet again - seems to be roll up your clothes:

At Midway Airport I got into a conversation with another traveler and I mentioned that my suit was packed in my carry-on bag. The guy couldn’t believe that I had a suit in my bag.

Not much luck with dress shirts though:

I don’t seem to have as much luck with dress shirts – I usually wind up ironing them at the hotel.

Regardless, I would suggest buying wrinkle-free shirts and trousers for such purposes. I had to pack a change of clothes in my backpack because I had to go for a company dinner after work (didn't want to go back home to change), and having flat-packed wrinkle-free clothes helped as they didn't look bad once unpacked.

I presume you're using a front loading backpack, right? If so, why don't you make a plastic or cardboard box that fits your smart clothes (add some straps inside to keep everything tight) and use it as a container for "keeping the wrinkles out". :D

Don't know about you guys but I usually never pack my backpack to the top and have enough room for about two or three winter vests (just an example) so that's where you DIY suit container can fit.

Not that you asked but there are travel irons that are neither heavy nor big so consider that as well if you don't carry your suit every time you travel.

Onebag.com at the end of the page dedicated to Clothes and Laundry advises to simply rent the suit when needed. But I presume that in a place without iron, such renting service will be hard to find.