There are so many great dry yeasts available these days, I intend to convert nearly every recipe I brew to dry yeast going forward. I will be running experiments to figure out my favorites.
That being said, I don't think a couple days of hot temperatures will necessarily kill yeast, whether it's liquid or dry. I wouldn't be too concerned about it unless maybe in the bottom third of the nation with a very long trek to get to your location. If only a day or two or even three, I think it'd be alright in most cases. But, of course, proceed at your own risk and learn from your own experience.