For my insulin, I use this portable USB-powered cooling thermos. It keeps 6 to 7 insulin pens around 40 degrees F as long as it has power. I have a couple different power bricks I use. Two are Anker 10,000 mAh power banks that last about 2-3 hours each (depending on external temperature), and the third is a big 26,800 mAh bank that lasts 8-10 hours. It can also be plugged directly to power when it's available in the plane or hotel (which is handy when a refrigerator isn't available). The sleeve helps insulate the thermos, and has a pocket for the smaller power banks and a lanyard to carry it. It also comes with a freezable gel pack, though to be honest I don't really use that. The reminder door hanger sounds dumb... but after accidentally leaving about $1000 worth of insulin at an AirBnB before I bought the thermos, I always make sure to hang that thing on the exit door on every trip.

This USB-C cable is the perfect length for connecting the thermos to the power bank when it's in the side pocket. Plus it's bent downward which helps keep it from being knocked out accidentally.

Everything else I typically just stuff into a bag that unzips and can be hung up, similar to this one. It is small enough to be considered a "personal item" for flying, or it can even be stuffed into a larger carry-on if necessary.