I did an overnight trip with the bag and it went pretty well. Just enough space for my laptop, entire washbag (which was overkill, but I was too lazy to re-pack a sub-set of it) pyjamas, change of clothes, laptop and phone chargers, LM Surge, 591ml (20 fl.oz US) KK insulated and (surprisingly) 946ml (32 fl.oz US) KK insulated in the side pockets.