For milder weather, as others have suggested, a gig bag with backpacking straps But in colder temps, and extremes in humidity (high or low), I'd be using a motor vehicle to avoid damaging the guitar. None of my guitars (all electric) are super expensive, but they aren't cheap, and I try to keep humidity and temp within a certain range in the room in which they're kept, or if going out with them this time of year, it's in a car.. The distance you're traveling may not be much, but still better to take care.