I have used my Invernos for Ice/Snow for a few years now, and they do the job. The only problem is that the inner liner slips about an inch from the outer shell when I crank on them hard. If I cinch down the outer shell to the point where there is virtually no slip between the liner and shell, I loose blood flow to my feet within an hour.

Anyone else have a similar problem, or suggestions to a solution?

An inch of slip sounds like they are simply too big for you, at least for technical ice. But that being said, I doubt an insulated plastic double boot will ever be as precise as a thinner single boot.

Scarps are built for those with wide feet. It sounds like your heels are not thick enough for the boot.
Either
-look in to another brand and boot (la Sportivas are skinny)

-tape up your heel to fill up the extra space,

-you may have to look in to an heel insert for your boot.

-lastly the Invernos is an plastic boot your local ski shop might...might, be able to heat the boot and press in the heel to better fit your foot.

The above advice is so useless and incorrect, I feel compelled to reply.

First, see if the shells even fit you. With a bare foot and the liner removed, stand with your toe just touching the front of the shell. You should be able to fit ~2 fingers between your heel and the shell. If not - it's hopeless - sell the boot. Google "boot shell fit" for more opinions.

Most plastics, including the inverno, don't have half shell size increments, just whole. So, if you're in the smaller of 2 half sizes for a shell, they claim the liner is thicker to make up the difference, but it really isn't by much and will pack out quicker anyway. This could be your case. Try the next shell down. Next time, choose your boot mainly by how good the shell fit is - ie, you don't want to be stuck choosing between two whole shell sizes. Fitting with the liner is a waste of time. I'd guess 80+% of first time plastic boot buyers walk out with boots too big for them.

If you actually like this brick of a boot, the shells actually fit and you really want them to work for you - toss your factory liners in the garbage where they belong and go get a thermo form liner - Intuition is popular.