80 degrees at night and warmer during the day for just about any tortoise species is much too hot.
If you are going to purposely increase your humidity (by pouring water directly into the substrate, ideally under the basking light/heat source) you certainly do not want to let your temps fall low---50-60s + constant humidity= can lead to an ailing tort....
Now, if you have a tort that you are not going to add constant artificial humidity to the enclosure then I completely agree here with some species enjoying/tolerating the cooler night temps....but would never mix those low temps with artificial humidity in the enclosure for any species of tortoise....
I did not recommend higher than 80 during the day, I simply stated to also leave basking spot as is so the tort has that option remaining in the enclosure....