I can get 4 queen sheets, plus 8 pillow cases in my 5.5kg Miele, I line dry usually as even with reverse tumble and splitting the load everything ends up balled up in the fitted sheet in the dryer.
The other way is 2 sheets and 4 pillow cases at a time, and split the towel load in half and do half with each load of sheets.
We spend approx 5 hours a week ironing, between, 10-12 dress shirts and another 8 or so Polo's, plus 50 hankies, 8 pillow cases and 20 T Towels. The rumples from overloading just dont bother me anymore, I just plough through all of it.
Having been partnered off for almost 6 years now and the convienience of seperate bedrooms, I dont tend to have to worry about staining either, thus I can wash full loads.