Kaladin technically already owns the land by the Windrunner River iirc, that's north of the Kholin Princedom and south of Aladar and Roion. Highprince Roion was killed in the Battle of Narak. If Kaladin were to become a Highprince, he could also succeed Roion.
Though admittedly Sadeas is more likely thematically. There's also the fact that Kaladin was from that region and served under their military.