I actually covered this possibility. If there is another team willing to pay him 25-30M behind the scenes (like I said unlikely) then he could reduce his salary to something like a $5M guaranteed contract so the Saints can release him as a June 1st cut.
But yeah, without another team in the background being interested that's a no go and I can't see another team agreeing to that before free agency starts. There might be some interest later after teams have struck out in free agency with Darnold or another QB but Carr will already be restructured by then.