I don't think the ambient temperature was really a concern to be honest, I waited for conditions to improve before making that first flight, as we had a strong crosswind for much of the afternoon, and this was early evening with the temperatures quite tolerable.
Life's too short to rewind motors mate - Paul McCartney stuck at it for just a morning before escaping over the wall and I'm of much the same mind, if not of the same wind
I've used those 11x7 props right from when the motors came out and when those were the recommended props. A while later, presumably after the burned out motors started coming back, the recommendation changed to 10x7 but I so rarely use full throttle in these models that I saw no need to prop down and haven't had any problem. The 10x6 that was actually fitted ought to be well within spec.
You might be right though, it might have just been a bridge too far for the motor, in which case replacing it with another one with the same spec wouldn't be the best option.