For the immediate future, Thompson and Despres can be put on LTIR. That, in addition to demoting Stoner and Larsson gets us about 6.5 million in cap space. Not that this is real cap space, since it is all based off of LTIR which is a daily savings, not an overall cap decrease, but it should be enough to get Lindholm signed in the short term while a deal was worked out.
There will be a move of some kind to clear actual cap space in the next few weeks as Murray and Lindholm finalize a deal. I'd wager it will be a combination of LTIRing Thompson and Despres, and moving either Stoner with something of decent value as a sweetener. The debate over what value of sweetener you need to add to move Stoner has been ongoing all summer, but there is no reason to assume that Stoner's value is so negative that packaging him with a good asset won't net us more than a low pick in return. I think something similar to the OP could be in the works, but I would be shocked if Murray doesn't try to move any number of other picks/prospects before offering one of Montour/Larsson/Theodore to move Stoner. If one of those D prospects was in fact included in a deal with Stoner, I would expect something of value in return. Not just a mid round pick. And I suspect it would have been done well before the season started.
What we do know is that Murray signed players this offseason, and just finished a big new deal for Rakell recently, and while some of his signings are highly questionable, he would not have spent money like that if there wasn't something already agreed to in principle or at least somewhat on the table with another team to help us clear cap. Him signing new players and re-signing Rakell to a non-bridge deal only makes sense if he has other plans in the works. Otherwise it is career suicide for him to be no negligent to our cap and budget issues. That is why Ducks fans aren't really sweating the details or worried that we are about to lose a very good prospect as part of a cap dump.
as a personal opinion though, I would much rather have to swallow a deal like Stoner and Montour for cap space and a pick or prospect, than see us trade Fowler. It's not that I am not high on Montour, or any of our D prospects. I just don't see the point in moving Fowler to sign Lindholm when you can move a prospect and have Fowler and Lindholm in your lineup each night.