A rem 700 or clone in a carbon stock from manners with a hunting contour carbon barrel is probably about as light as you can get. I think Kelbys makes a titanium 700 action that can lighten up some weight.
The one and done caliber would probably be 300 win mag. Readily-ish available in factory loadings. Recoil gonna suck but whatevs.
Optics wise I would look pretty heavily at March. They have done lightweight and durable very well for over a decade now. You won't be giving up much in glass quality compared to a TT/schmidty. Find a lightweight mount and base. GTG
The one and done caliber would probably be 300 win mag. Readily-ish available in factory loadings. Recoil gonna suck but whatevs.
Optics wise I would look pretty heavily at March. They have done lightweight and durable very well for over a decade now. You won't be giving up much in glass quality compared to a TT/schmidty. Find a lightweight mount and base. GTG