Actually, even though I still stick to some imperial units because of tradition, I think it makes sense to go all metric when possible. For one thing, imperial is truly in the minority now and a common measurement language would greatly help international project teams. It's like if everyone in China dug their heels in and refused to learn English, so any time you spoke with them it had to be in Mandarin. It's hard to relate quantifiable amounts between America and the rest of the world, to the extent that unit converting apps are basically American translators.
I don't know exactly how cold cold is, or how hot Hades is, but I do know where water freezes and boils at standard pressure. Water freezes all around me naturally and I boil water for cooking regularly. I have never used a saturated brine solution in everyday life. I'd imagine the only time I would is if I was calibrating a thermometer or trying to grow my own salt crystals. I never relate the temperature in Celsius to 100 when I read it. -20 is pretty cold. 20 is pretty warm outdoors - a few degrees below room temperature. -30 is dangerously cold and 30 is uncomfortably hot. Go another 10 either way and there's a pretty good chance of dying in that temperature.
Also, it's just wrong to say metric is impractical or has no benefit in daily life. You could measure something and tell me it's 3 millizubs. I don't even know what a zub measures, but I can tell you already that that is 0.3 centizubs, 0.03 decizubs and 0.003 zubs, which would be the base unit for that measure. As opposed to 12 zubs in a pob, 8 pobs in a fween, 11 fweens in a fof, etc. If you tell me there are 3 ounces of something, I have to figure out if you mean fluid volume or weight. In fluid, if I need a small measurement I guess I'd use a dram? Easy - 1/8 of an ounce - you'd know that if you'd explicitly studied it beforehand... but you'd have to check if it was a US or commonwealth dram, and if you're measuring spirits then it's about 10x as much than if it was another liquid! (Well, technically in the US it'd be 8.115365448442319x as much...) If it's weight, is that an avoirdupois ounce or a Troy ounce? ...since those are the top two of the six most common ounce weights. Is a gallon a US liquid gallon, a UK liquid gallon or a US dry gallon? To me, it seems there are so many ambiguous interpretations of imperial measurements it's like a deliberate attempt to miscommunicate and get something wrong...
(edit: haha... water never boils at STP)