I'm currently very tempted to do exactly as the title says. I'll write something down to clarify my thoughts to others and especially myself. I currently have two (centerfire) rifles, and a 22LR and a 17HMR.
My large game rifle is a pencil barreled 30-06. It is adequately accurate, works as intended and I don't really have too much to complain. What I slightly dislike about it that the thin barrel gets hot real fast and causes plenty of mirage on range that distorts the scope image. It also is not superbly accurate. It can hold most ammo within 1 MOA for 5-10 shots but it seems to be somewhat sensitive to any changes (temp, support etc). It has a really nice Steiner M7xi scope on top of it.
My varmint/range rifle is a 223 with 1:12" twist. What I like about it is that it is really accurate with certain loads, easily sub-MOA. The recoil is light and it is easy and cheap to shoot and reload. The powder consumption is small, cases are easy to resize, the bullets are cheap etc. What I don't like about it is that the slow twist rate that prevents the use of ballistically efficient bullets. Anything past 300 meters is ****ing in the wind.
My hunting is mostly from a blind or other static location, so I rarely have to carry the rifle more than a mile during the hunting day. I mostly hunt white tailed deer and raccoon dogs with an occasional hare, fox or roe deer in between. I've lately also become interested in learning and competing (mostly to evolve as a shooter, not so much to win) in PRS. None of my current rifles are well suitable for that. The 30-06 is not a good fit for a rapid course of fire and the 223 is ballistically inferior.
I'm somewhat of a minimalist by nature and now I find myself considering buying a third centerfire which also would need a scope, suppressor, dies, scope mounts and all that. This has led me to considering replacing both my existing rifles with a single varmint or semi varmint, most likely a Creedmoor. Throw the Steiner on top of it, fit it in a nice stock and do everything with it. Sure, it is a bit more expensive to shoot and reload than a 223. Sure, it does not have the oompf of 30-06. But there are certain benefits in using the same rifle for practice, white tail, raccoon dogs and PRS.
Driven hunts and moose hunting are something I very rarely actually do. This rifle wouldn't be the perfect tool for those, but I think it could be manageable. I also have the small, light and easy to carry HMR for smaller game and the 22LR for practice.
I'm thinking of something like a Tikka T3x CTR or (super) varmint in 6.5 Creedmoor with a Steiner M7xi 4-28x56 on top sitting e.g. in a KRG Bravo. I don't really see much cons in replacing the two rifles with a single one. It will definitely be suppressed, so a 20" barrel most likely would be my choice though it is not the perfect solution for a PRS rig.