Well, I'm with FireForged in post #29.
I tend not to over-analyze this sort of thing. I've carried a badge and some sort of duty/off-duty weapon for more than 30 years, and I just don't see the need to carry a rifle or shotgun for personal defense while traveling.
Before I retired, when I traveled for work, I was carrying either my issued service weapon or an authorized off-duty weapon. Whichever was used, that's what I'd have used for any necessary defensive situation when I was driving or taking overnight lodging.
Now that I'm retired, it's whatever handgun I'm taking along under LEOSA (if traveling out-of-state).
At the moment, for an out-of-state driving trip we've been on, I decided to take along one of my J-frames and my LCP (since the LCP is enough smaller to be more easily pocket-holstered in a couple of my jeans pockets). The J-frame is a chambered for .357 Magnum, but I'm carrying it (and some speedloaders/speedstrips) loaded with some of the usual +P loads I commonly use.
Granted, I did pack a 50-rd box of some GDHP loads for each of my guns in one of my bags, as that's a habit I formed years ago when traveling armed away from home for extended periods.
Having taken long guns to outside training, safe/secure storage of one while away from the vehicle or motel is a concern I'd just as soon not have to deal with, especially now that I'm retired.