I looked up your MH online and it showed a GCVR of 20,000 not 22,000. Either way if your MH is within its weight rating of 14,600 you can tow your trailblazer if it is able to be towed 4 down. It appeared from what I saw that you do have a 5,000 weight limit for your hitch.
In regards to a dinghy towing guide, MotorHome magazine publishes one every year. Do a web search for motorhome dinghy towing guide and you should find all you need to know. Hope this helps.
2015 Georgetown 329DS
2014 Chevy Equinox