Totally disagree. You can have perfect temps the whole incubation and compromise your hatch with too high or too low humidity. Too low temps by that much are going to cause significant delay to development with a high probability of defects. Temps too high by that much run a risk of "cooking " the embryos excellerated development which again cause cause extreme defects/deformities in chicks. My first hatch was compromised by too low temps because I trusted one new thermometer w/o checking it first.
Eggs are a lot stronger than we give credit for. I used a couple fridge eggs in one of mine to see if they'd develop too. (And I have my doubts about wether eggs need to be turned before development is present.) I've heard that using refrigerated eggs allows a higher hatch rate for older eggs as a means of suspension-so to say.
Honestly, this is what I would do. First thing, calibrate thermometers. At least check them to see how accurate they are and use 2. Never rely on a thermometer that hasn't been checked. 50% in my opinion is too high and often leads to many DIS because of drowning or growing too big too hatch. Consider doing a low humidity incubation and checking the air cells on days 7/14/18. That will allow you to know when and how to adjust the humidity so that the majority of your eggs are getting what they need. 2 hours away isn't bad, but the handling at the post office and in transfer can still affect the hatchability. I would consider getting local or making the drive if you really want eggs from that source.
