Google Maps can be your friend, or Scout, or iPhone Maps, and I am sure there are many others. Not sure why you had to look for someone when there is more than 1 app out there. As for the tire size, I have a spare, yet the jack used on your rig will not even lift mine, so yes, size does matter. I also don't care where the dispatch center is, at least it is not in India, and even not being from Texas I can understand them through their accent.
As for the 3 hour wait, I would have had a snack, walked the dogs, and relaxed. While I still work, life is to short and I am not in a hurry, when I get there, I get there, at least I made it, which is what counts in my book.
Safe travels!