Give us a laptop type. Note the charger the manufacturer ships with is almost always overkill. People had success with charging the ThinkPad X1 Extreme with various USB C chargers despite it ships with a 135W and USB C tops out at 100W. I regularly charge my ThinkPad 25 with the 45W Mu One despite it shipped with a 65W charger. https://9to5mac.com/2018/09/25/60w-u...-all-macbooks/ tested 60W vs 87W for a Macbook Pro and the results are clear: "after an hour and a half the 87W charger offered 4% more battery" and after that both only outputted 40W.

Of course, if you are going to Furmark your laptop on the plane this won't work. I know some people pushed the X1 Extreme to consume 111W. But that's still quite far from the 135W it ships with.