Ha ha ha. A man after my own heart. Yeah, I did that a few years back - decided to go "just one" rifle for all large game, deer and up, except for dangerous game. After much research and hand wringing, I settled in on my .280 Rem with 139 Interbonds in a Wby Mark V (and a Browning A-Bolt II in .375 HH mag for if I ever get to the dark continent). The goal was simplification of hunting guns and thus life. It would have worked well, I think, and still would if I could actually stick to it. It didn't affect varminters, self-defense rifles, shotguns, or handguns (or archery equipment, though I simplified those, too, from 6 down to 3 bows & crossbows about 4 years back). I had sold / eliminated big game rifles in 7mm RSAUM, .280 AI, .270 Win, 9.3x62mm, .260 Rem, .35 Rem, and possibly others I can't remember. I also fought off the strong urge to get a Kimber Mountain Ascent in .270 WSM or .280 AI.
Sadly (or not), I was tempted by deals on gunbroker and elsewhere here and there and ended up slowly "rebuilding" with rifles I felt that I had to have (once the deals were found), especially since it's a massive buyer's market in the last 10 months for guns in this "trump slump", and then justifying each one in my mind, so that now I'm back to where I was - too much complication. So now I reload for a .243 (have two but use factory in one of them), a .25-06, a 6.5x55, a .280, and a .30-06. And I admit I'm thinking of adding a .416 Ruger to the mix, and really pushing to get to Africa before I get too old.
So honestly, I do need to follow through and sell the "big game .243" (keeping the "varminter .243"), the .25-06, the 6.5x55, and the .30-06.... But each of these are rare / special in some way: discontinued / sought after / limited edition type stuff, so I can't bring myself to sell any of them; and ditto the .375 HH mag - it's a Medallion and the wonderful A-bolt II has been discontinued and replaced with the crap A-bolt 3.... similar stories on the other four that I "should" sell off but no way I would.
However, as a compromise, I just decided this hunting season, after scraping up my .30-06's beautiful stock falling more than once on a rock bed at 8200 feet looking for elk, that I'm going to simply turn some of them into just "range queens" to pass on to nephews someday or some such (luckily I have one nephew who is going to be a big hunter), and hunt large game solely with the .25-06 and the .280 (not counting the .375 HH mag), which both have beat up composite (though expensive) stocks - no pretty wood though. Then I can re-finish the stocks on the other three, make them range-only guns, and start shooting them with cheaper target bullets instead of premium hunting bullets. Those two which I will continue to hunt with are also my lightest two, and offer a good balance for all game up to moose and inland brownies, so that's why I chose them in this compromise toward simplifying I came up with, even though I generally hate the idea of owning a gun which doesn't have a purpose.
FWIW, I keep a speadsheet in MS Excel of what is sighted in, with what exactly, at what range, with which load, and if I plan to change that, to which other load - also shows what's the priority of rifles to sight in among those which are not currently sighted, along with tons of other stats on each gun - it's a huge database. I recommend this.
Tangentially related: I WAS able, over the last 20 years, to reduce all handgun chamberings down to just three (not counting my .22lr revolver): 9x19, 10mm auto, and .45 Colt, and shotguns to just two: 12 ga and 20 ga. No way I could do that with rifles... Let's see, all tolled, there are 14 rifle chamberings here if you count rimfires too - 15 if you count muzzleloaders. It would be extremely painful to pare down to 10 rifle chamberings, let alone three.