Hard to beat that routine, hit the specificity and get some strength work in and thats about as good as it gets. Only issue is that for lots of guys, they just don't have time/access to hit the trails for 2-3 hours a day.I don't know if you call what I do a routine, but it seems to work.
I'm hiking 3-4 miles daily on local single track trails, with one day concentrating on steep stuff and one day upping the mileage to 8-10(+). These hikes are mostly in Zone 2- ie not overly arduous (some of the terrain will bump the zone up a bit). I strength train twice a week using a modified Wendler 5/3/1. I spend a lot of time on snowshoes and backcountry skis during the winter and backpack year round. Lots of time on my feet.
About eight weeks out I start adding a weighted pack a couple of times a week. I start with 30 lbs (two weeks), then 45 lbs (two weeks) and finally 60 lbs (also two weeks); the last two weeks before hunting season I cut the weight back to 30 lbs. The weight is with sand bags, the actual weight with the pack/water/etc is probably close to +10 lbs over that.
Like I said probably not a "routine", more of a lifestyle, but it works