It's probably a little overestimated, but I think that your "maximum 10 Celsius" is underestimated
Again according the original article:
There is a difference between "crumbling" an entire construction, and dislodging a few blocks at the angle of the same construction. The phenomenon of thermal expansion dislodging blocks in a natural wall has been documented by the geomorphologists, for instance here.
Please note that I do not think that all the casing stones fell from thermal expansion. But this mechanism, in my opinion, fits quite well particularly with the Bent Pyramid, where it would at least partly explain why the casing has disappeared on the angles and not in the center of the faces.
The maximum/minimum average in Giza never surpasses the 10 degree mark (according to the Egyptian meteorological office), that is the point ignored here and with those 10 degrees the maximum expansion of a whole row of casing stones could not have been more than a few tenths of a millimeter, that and given the fact that the casing stones did not rest on each other but on the block ledges being held with mortar against the rough side of the construction already makes the whole theory have a gap a whole herd of elephants can run through.
The other hole is, as I mentioned, as soon as they have the gap (again, of a few micrometers) they stop working against each other, which is the other part ignored in that theory.
And yes, Giza surpasses 30 degrees, but those conditions also existed when the pyramids were built so the likelihood is that the expansion gaps were already there before the construction was ever finished. If the casing stones would have been as long as the pyramid itself I could see the merit to this, but given that they were relatively small and set in a gypsum bed (which means that they would have had gaps already very early on because the gypsum would be the first to go under the expansion pressure) plus that the casing was angled inwards (as we can easily measure from the still existing) of the face and not straight, this whole scenario is less likely.
Last not least, we have historical reports of people "mining the pyramids" for building materials in the last 7-8 centuries.
The only possibility I see is that temperatures suddenly tripled or quadrupled from the previous night temperature. But from the records we have that is very little likely. And it would mean that on some given day there would have been a maximum temperature of over 80 C (Celsius, in Fahrenheit that would be around 180) that lasted long enough to heat up the blocks to the same temperature. If that happened we would surely know about it because it would be recorded as the day all inhabitants on Cairo died.