In your example no, they don't return to a barn at night. They roam the land grazing. And as for a barn.. doesn't have to be. Many ranchers load up hay and take it to designated grazing locations. The cattle quickly learn. What you have described is basically why there are 'round-ups'.... where you ride out, or these days use a pickup, ATV's, and herd the cattle to corrals where they can be tended too... branding, innoculations, etc.
I'm not sure but Deadpool, I think, has a more compact setup in which the barn is probably used a lot but I very much doubt the cattle use the barn at night... perhaps for cows ready to calve. Most of the cows you see in movies in a barn stall are for milking... not fattening for slaughter.
On my ranch we have 5 different pastures, fenced off. As the land is grazed off, (wild oats), we alternate them through pastures. Feeding on my ranch is mostly a winter chore when feed is scarce OR this year year-round due to the drought and a weak natural feed year.
I have been invited to help in a few round-ups in other states where they have HUGE tracts of land. It can take a day or more of riding just to get to the cattle.
Predators, yeah... ranchers aren't fond of them.
Where I am lions are very protected and illegal to kill. Lion populations have been exploding in Calif. I would expect some accommodation in the current laws soon to allow for ranchers to control lion populations.. BUT... I'm not involved, personally, in ranching so I don't stay current on the topic. Lion population is also exploding near some of the big cities, like LA.
Trans-Canada Highway... I envy you.... I've looked into it often for a motorcycle trip but never quite got around to it.... but WOW... that has to be spectacular. - JamesJM