My ghost square is rated at 140 kg (308 lb) total weight (bike, rider and luggage). I'm about 180 lb, so I'm confident that I will not get to that limit of weight because presently I have about 70 lb of stuff.
308 - 70 (gear) - 180 (me) = 58 lb. minus some more for two water bottles and my handle bar bag, maximum two days of foods, I'm still far from the weight limit. This is without considering reduction on my gear.

Thinking also of putting camping gear and light stuff on the rack pack. I will also get the ortlieb front panniers and will transfert my Arkel trunk bag (use for small items, fruit, nutrition bar) on my front rack for easy access (instead of under the rackpack). I should be fine with that set-up.