Travel light, go far. Such is the mantra of the backpacker, the frequent flyer and Cesare Pavese, the celebrated Italian writer who first coined the phrase. There are, of course, few greater joys than skipping through airport security with a small carry-on and your liquids pre-packaged and then strolling straight off your flight and breezing past baggage claim. And as anyone who has ever hiked, biked or otherwise carried their luggage for extended periods can attest, it helps if you can leave your just-in-case outfit at home.

Yet as liberating as it can be, the trend of packing light—as popularized by travel influencers and “ultra-light” packing guides—has perhaps gone a little too far in its own way. Neglecting to take the right clothes for the climate or, for that matter, enou...