The Canon EOS R5 must be recalled now as this is so far from acceptable. It appears that only 1-2 hours into a stills shoot you can toss aside the Canon overheating test data in the real-world.
In an update to the test at DPReview, Richard Butler found this out the hard way as he describes below.
The real story is not the continuous recording cut off at 30 minutes from cold in normal room temperatures, but that the limit is closer to 2 (or even zero) minutes during a day’s real-world shooting.
Read moreThe real-world 4K HQ overheating limit is 2 minutes on the Canon EOS R5 say DPReview