The first question is why are you trying to get temps over 92ºF? I would actually giving the potential error of the accurites I would actually drop it to 90ºF inside.

I also have a number of holes in the tubs on the advise of John Rossi DMV, and Don Benoit DMV. There cannot be too much ventilation only too little. The problem is what is too little? The rule of thumb I was given is simple if the water bowl is removed (source of humidity) and the substrate (paper) is dry, the humidity should settle to the room's RH in 2 hours or less. (2 air exchanges per hour give or take) I have humidifier (warm mist type) in my room with the rack it keeps the room at 60% RH and the rack stays basically the same as the room. If you were holding much more than 10% RH over the room I would be concerned personally about too little ventilation.