Question here. Do you mean that you buy them 2 sizes larger than your fitted size? If so, wow, hadn’t considered sizing up, but that’s a great idea for minimizing conductive losses while allowing for a liner inside, and still avoiding crushed insulation.
Second question: when you change the liners out every 45min… are you putting in a new liner every 45min or are you swapping through another recently used liner in a liner rotation of sorts? How many pairs of liners are you carrying?