You may not believe it, but the carry over should help them get to 100 million in cap space and they should use it in 2025.
What evidence do you have that supports that they will use it, especially in free agency?
I mean, it's a nice wish, but the Joneses changed their philosophy concerning free agents after 2012, when they overspent on Brandon Carr (based on the return of investment). They've had opportunities to spend in FA since then and have chosen to go cheap each time. We have nothing to go on that that will change except hopes.
The Cowboys' pattern is that if they have money, they will spend it on their own, rely on the draft and fill holes with cheap FAs (either washed-up players or ones who flashed a little potential).
Since you've lost all your hope for this season that you thought was going to be great despite the lack of FA signings, I guess you want to put your hope in something else. I'm a proof guy, though, and there's just no proof that they'll do anything to fix the holes. In fact, I won't be surprised if they blame this season completely on injuries and double down on doing nothing. (Doing nothing means leaning on the draft, re-signing their own players, maybe making a couple of low-cost trades and not spending more than a few million on any outside FA ... I'd put the cap at $3.5 million for a one-year deal since they gave Kendricks $3 million this year.)