I have a 60 litre Trailblaza,
Had the same thoughts about the weight factor, not so much for myself but when the bride decides she needs to get milk for another cuppa. We got a MSA slide fits on top of the drawers in the back of the 80 and drops to just above the tailgate. The 60 allows the bride to just reach the bottom of the fridge while standing flat footed, she is height challenged. The MSA and other decent drop slides come with gas struts to help with the lift of the fridge so it's not like you are trying to lift a dead weight of, in your case 100+kgs. The bride, also strenght challenged, can still lift the fridge and slide it away after she gets the milk for her cuppa.
If you get the slide for your fridge you will find a bigger gas strut to help with the lifting.