ccordaro,
I think you have a different problem from the majority of cigar smokers; you have too high ambient RH, and most of us have low ambient RH --- we are usually trying to add moisture in the humidor, not remove it, hence some of the confusing advice.
A room dehumidifier will not help, since your home windows are likely open. A "dry box" will not help since its RH is 85%, so it's not so dry. Opening the humidor for a while will not help, since ambient RH is too high, not low.
First, make sure you have a tight seal on your humidor; you may need to switch to some airtight tupperware to better keep unwanted moisture out.
Second, the higher PG to water mix may help; but from what I've heard on this forum about Climaxx beads, they may be even better --- seems there is a 65% Climaxx bead available, and you need all the help you can get. A dish of rice or saltines will absorb moisture, but not control it. A dish of salt will absorb moisture and try to hold it at 75%. More is better. All of the above may have to be dried out once in a while (in the refrigerator should work), the opposite of our adding distilled water to our humidifiers.
Third, try to keep space for air circulation between your cigars. That's not easy, with a crowded humidor and when opening and fanning the lid increases your problem, but air circulation will help prevent mold.
Your wide temp variations aren't good, as well as the 84 deg high it gets to; if you are eventually able to control the humidity with any of the above advice (say "airtight"!), the cellar would be the better storage location. Otherwise, freeze all new cigars (search for that) to supposedly kill beetle eggs.
Hope this helps, and good luck.