I've learned finding a tire can be a difficult thing. 8 years ago my wife and I did a trip through Vietnam, Cambodia and Thailand. We landed in Ho Chi Minh City, unpacked the plane traveled bikes and threw them together the next day. Then on day 2 started riding. about 100 kms out of Ho Chi Minh had a flat. No big deal right, except the flat was caused by my brake pad rubbing on the sidewall and wore it all thin till it finally broke through and popped the tube. Thought crap and pulled out my spare 26" folding tire, problem solved right. Except not because it was a 27.5" hybrid tire that I had purchased by mistake somehow. Well I put a big patch on the inside of the tire itself and threw in a new tube. From there we limped the last 20kms or so to a fairly large city. So it was a pretty big city and a full day and 9 bike shops later we found a single 26" tire that the bike shop owner was shocked he had. I wish i could tell you if there were lots of 700 tires but as our search was a little dire the only thing I was focusing on was if each bike shop had a 26" tire. All this said I would never do any kind of trip of length without a spare folding tire (triple checking it is the right size,ha). In my mind a spare folding tire is small, light and a must!
FYI cycling out of Ho Chi Minh was easily the most insane biking I have ever done. Largest vehicle has right way for everything, not a single traffic light just traffic circles at all intersections and scooters jam packed in every open road space and sidewalk as far as your eye could see!