X2 on what bikendan said. You are looking at a very dangerous combination here. here is a great article
to better help you understand the dangers of towing of grossly overweight combination. It is not just a matter of towing slower, you still need to be able to control the trailer in a sway situation from a wind gust or in a panic stop when done one pulls out in front of you or a deer jumps out from the woods or whatever. These things have happened to rvers on these and other forums I frequent.
I have towed a tt with an unmatched TV. It was a Nissan Armada towing a 30 foot TT. It was better matched in weight than you are... towing capacity of 9100 lbs, payload of 810 lbs. Trailer weight 7300 lbs loaded (570" lb dry weight/7700 lb gvwr) and loaded tongue weight of close to 1000 lbs (dry tongue weight 800 lbs).
Cars, trucks, suvs,,etc would pass me and make my trailer push my TV all over the road. Anything upwards of 50 mph resulted in handling issues, even when not being passed. I tried everything to fix my handling issues, LT tires, hitch adjustments, redistributing weight throughout the trailer, etc. The final straw came when I got pushed down a 7% grade on a twisting 2 lane mountain road. It was only about a 2 mile or so down hill but steep enough to cause issues. I fownshifted to low gears, pumped brakes, alternated between truck and trailer brakes etc. By the bottom my brakes were cooked. That is not a good smell. I swore then and there never again. We stayed to short drives on the flat until the new TV could be purchased. We bought a used F250 diesel within a month or two of that trip. What a difference. I drove that same mountain road with the same trailer but now the 250. I touched my brakes 1 time going down the hill. The weight of the truck and the capability of the engine kept me slow enough not to have issues. This lesson was a good one and it fortunately worked out for my family.
Please read this story
where a family towing a trailer too big for their SUV crashed. Both parents and one of their kids were killed in the accident. Also be aware there are attorneys out there that will use for overweight rigs if they cause an accident. More on that in this thread.
so please please think before you try this. Sell the Trailblazer and get a used vehicle that can handle the trailer or get someone to tow the trailer to a seasonal site for you. This way you can enjoy the trailer and not have to tow. Some campgrounds store the trailers on site. When you are ready, you simply call ahead and the campground will move the trailer to your site for you. So there are other options for you.