Hey those 265s look great!
I put 245/65R17 Blizzaks on those same rims you have for my winter setup. The 245s are a half inch bigger diameter than stock wheels.
I wanted to go to the 265s like you did, but I wasn't sure if they would fit! But I see they will, so when the current set of Blizzaks wear out, they are getting replaced with 265s like you have.

I feel your pain taking the summer rims off.
My 19s are sitting in a stack in the storage garage. Right next to my snowmachines! Heading to the Alaska Range this weekend to go riding.
But those Blizzaks sure hook up in the snow. The X5 is a beast in the slick stuff.