Another suggestion that I think would really stretch them into something new, I would love CDPR to pick up an old franchise from Chris Robert's Origin, which failed after they got bought out by EA. I would love to see a modernized return of the Wing Commander Series, with a strong CDPR RPG elements to compliment the Space Opra / Simulator origins of the game. I could just imagine what the talents at CDPR would do with the enemy Kilrathi
Not a franchise, per say, but I've always wanted a game like Wing Commander that merged flight sim stuff with "ground" combat and an RPG story. Star Wars Battlefront II (2005) scratched that itch a bit, but I've always envisioned something less twitchy. A solid flight sim, ability to command capital ships eventually, fight through the corridors of larger vessels, explore planets, character development, and a branching campaign.
There were 2 games from the '80s / '90s called Rules of Engagement and Breach that you could use together. Rules was all about capital ship combat in space, and Breach let you conduct boarding operations similar to XCOM / Jagged Alliance battles. I always used to think, "This should be in the Wing Commander universe, and there should be a story, and we should be able to control our guy...!"