A few things that many have said and I will repeat in hopes that you understand:
#1 - 200* for your transmission fluid is completely acceptable. On my TV I can tow all day long and it gets (and stays at 210*). I pull in the mountains here in WV and have pulled my TT all over the US. In the Texas heat (I am originally from TX and often go back) it will climb to 240 when doing stop and go traffic or in town. It quickly cools back down to 210 after I hit the open road in 100+ heat.
#2 - When was the last time you had your transmission fluid flushed and the filter and fluid changed out? The ability of the fluid to act as a lubricant and reduce wear lessons the older and more often the fluid is used. Reduction of the friction is the main job of the fluid - friction is what causes heat; therefore, you should change your fluid in accordance with your owners manual (or more often if you wish).
#3 - Have you had a mechanic ensure your transmission coolers lines are installed properly? It may be that your trans cooler fins need cleaning and that you may not even have an auxiliary transmission cooler. Almost all vehicles (if not all modern pickup trucks) have a trans cooler and the lines will go from the transmission into the side of radiator where the radiator fluid helps to cool the transmission fluid. If you consider that your radiator fluid is likely at 195* when operating your vehicle (since most modern gas engines have 195* thermostats) it is not unlikely that your transmission fluid would be close to 195* after it has been in operations for a while. The added weight of a trailer would easily cause the slight increase in temperature. If you have an auxiliary transmission cooler than it will provide additional cooling of the fluid. This auxiliary cooler would be on the outside of your vehicles radiator and would be visible when you open the hood of your truck.
#4 - What does your owner's manual say (if anything). My simple research on line has a lot of good as well as misinformation on the "normal" operating range for transmission temperatures. I read in one link where Trailer Life Magazine back in 2009 stated that anything below 240* was acceptable for the modern transmission fluid and I saw another post in a GM Forum that said anything beyond ambient +100* would "cook your engine" (misinformation since almost all transmission lines run through the radiator). And when ambient temperatures are low we want them to be warmed up to help with the thermodynamic fluid movement and to help reduce wear (I won't get into the engineering side of thermodynamics of heat transfer in cold vs. hot oils used as a lubricant).
Finally - if you are looking for the members of this forum to provide you an excuse (permission) to buy yourself a new TV b/c you want one...then go right ahead and yes - the "GROUP" says go buy a new truck...just ensure you post pictures :)