Long time dog owner, and have always trained to have well behaved dogs, but have almost only ever had mutts. I'm curious however, as to what specific breed would fit my life best.

I drive truck for a living, as most of us do, and as a result I'm not anywhere near as active as I used to be, with about 60-90 mins split between 2-3 outings per day. I spend most of my time alone, but would need my dog to be friendly enough to be able to take out around other people and to public places without issue, but also be able to be protective of my truck at night, or if I have to step away from it for an hour or two. 40-120lbs is a doable range, as that's well within my abilities to lift and lower from the truck. Must be both heat and cold tolerant as I run across the entire lower 48, Canada, and Alaska where I see temps between -60f to 120f. Training difficulty ideally between easy to moderate, and high intelligence is a major plus.

In other words, I'm trying to find this perfect dogs purebred equivalent for after she inevitably breaks my heart.

Ms. Biscuit for reference pics of my current beautiful road pup, as well as for your attention/enjoyment.