If your HG suit is made for UK and N. Euro climes then may be too warm (even with vents) in HOT/Humid conditions. THICKER Cordura type fabric is used ... does not breath well, despite claims.

My Textile jacket is a light weight Cordura variation, flows lots of air. Not good in cold Winter conditions. Not all Cordura is the same!

Your HG should work GREAT in High Altiplano riding through Ecuador, Peru' and Bolivia, probably good in all day rain too.

In high heat you may have to UN ZIP to the waist and open all vents.
Best thing about your Tourareg suit will be lots of pockets!

On shorter rides I still wear leather pants combined with Textile jacket. I'm OK temp wise up to about 85F degrees. Above that into hotter climes I use mesh/armored textile pants (Cycle Gear Sedici). If Really hot I use Rev' It
Textile Mesh jacket. Quality, armored Textile mesh gear is best I've found for truly hot, miserable conditions. If things go cool or get wet, I slip on rain gear over and add layers under. (or heated gear)

I treat my leather pants (and boots) with special leather conditioner called SNO-SEAL. It's a Bee's Wax product. Used it over 20 years, works well and makes my boots and pants fairly waterproof. Also treats leather, keeping it nice and supple. I apply and put into LOW heat warm oven for 10 minutes. (150F max)