My temps run 190*+ too. An internal thermostat doesn't even open (and allow flow to the factory cooler) until just about 185*. When towing, it will sometimes go up to 210*. So, you have some choices:
1) Another cooler, either in place of or, in addition to the factory cooler. In this case, I definitely recommend only the Tru-Cool 40K (low pressure loss, 40,000 BTU).
2) The thermostat on the trans. There are two videos out there, one guy reversed the actual thermostatic device and spring, one guy removed it and drilled-tapped heads for a 1/4" pipe plug. It has a pin in it and is filled with a fluid that expands with heat, pushing the pin out and re-directing trans fluid flow through the cooler. Personally, I would do the reversal method as you can easily put it back to stock. This allows the fluid to flow though the cooler all of he time. This could be a problem if you have some seasons where it gets very cold and the fluid will never get warm enough. To date, I have not found a way reduce the temp at which it will open. Still working on it (kind of)...
3) The trans pan (this is what I have done, so far). Get a deeper, aluminum pan that will hold approx 2 quarts more fluid and help cool the fluid. The temps still go up but come back down quicker.
4) I wrapped the crossover pipe, where it runs right next to trans pan, with header wrap, to help keep heat off of the pan. I can do this because I live where we have essentially no car rusting issues. Some say that the header wrap will absorb and retain moisture, causing the pipe to rust quickly. I think that if you are driving it daily, it may not cause any more rusting then normal. On my Dodge Ram, I also installed a baffle on the crossover pipe. The baffle was an old chrome dress heat shield off of my Harley. This was to re-direct air flow off of the pan.
I would do #4 no matter what you decide. It can't hurt.
Now, that said, by most accounts, the new trans fluid is fully capable of going up to 210* or more without issue. And, with GM using that thermostat set at 190*, it "should" be okay. If in doubt, replace it (easy to do with the new pan, it has a drain plug) more often. Say, every 15k-20k miles vs 30k or more.
