I am on record here as someone who likes to travel light. For me, comfort is climbing hills with ease (well, with less pain and effort). Of course, I still want a spaceous enough tent, a good stove and a warm bed. Even in cold and wet weather. So in July when touring in Norway, and prepared for the worst weather, I had a total of 18 kg in a bar bag, two rear panniers, and the tent on top of the rack. The bike handled fine, but I also think in my case that with anything more it would no longer do that.
Some 2-3 kg of my luggage was bad/cold weather gear that I would not often expect to take, and on my return I also concluded I could save another 2-3 kg by leaving unnecessary stuff at home (cheap) and by getting some lighter kit (expensive). So for normal temperate weather my luggage weight could be reduced to some 13 kg, without any deprivation. Finally, I also concluded that this could be further reduced to about 11 kg, but with some deprivation of comfort that I decided I did not want to endure. It is a fine line, that you wil have to draw. However, you seem to have made some sensible decisions so far. Doing without fron paniers saves some 2-2.5 kg, and quite a bit of money. You may be better off spending that money to reduce the pack size and weight of the gear - I think.
Willem