For me, I have one dedicated to long range because I want feel as though it is second nature to know the ballistics of that specific rifle. Several others are hanging around but my hunting focus is in one gun. Certainly not saying my way is right, it's just the way I do it.
Last season I sold my 338 LM while awaiting my new 338 LRKM. I was not sure how my hunting season would go with only my 300 win. By the end of the season, I had more confidence in that rifle than any I have ever owned. Plus I made my longest cold bore shot on a game animal ever at 1285 yards.
As the old saying goes,
"Beware of the man with one rifle, he probably knows how to shoot it"
I shoot my .338 RUM 99% of the time, but sometimes you need to hunt a bit closer to houses (like on farms) or you quarry is a bit light skinned. Then something a little less peppy is nice. But for the most part I am a one gun man.
see I am starting to lean to that 1 gun man thing. I have a few toys but think I might want to focus on just one.
As far as long range rigs are concerned, even though I have a few, there will always be the favorite that I have most confidence in and prefer to use. To really excel with one it takes time, a lot of testing of everything and all the practice in different conditions we can muster up. The better you know that one long range rifle, the happier you will be. Then an old stocker in the back of the safe for those days where you will not need the precision rifle. One where a 300 or 400 yard shot will be it. But I haven't dug one of those out since 2007.
Rifle choice(s) depend a lot on how far and what you're planning on shooting. I'm pretty much a 2-gun sorta guy.
A 1st rifle used for everything out to long range - say from 0 to 700-900 yds depending on what I'm hunting. For that, a 7mm/300 win mag wildcat is what I'm planning on. That chambering will be excellent for anything I plan on hunting out to my self-imposed distance limitation.
A 2nd rifle used for what I think of as "Extra Long Range" - from 700/900 yds out to my (currently under-developed) shooting ability, a chambering of *much* greater capability is needed. For that, I've decided on Kirby Allen's 338 Raptor wildcat. It strikes a brilliant balance between the common big 338's (RUM/Edge/Edge +P/Lapua/Lapua AI/etc) and the truly monstrous 338's (338 Allen Mag/338 Chey-Tac/etc).
So that's kinda my thinking on the "One vs Many" approach.
PS - I must admit that for strictly short range hunting, a Marlin 1895 45-70 (with some hot handloads!) would round out any hunting range or game I would *ever* encounter.