Like his sister Missy, Georgie’s future is already set in stone by the events of The Big Bang Theory. After Young Sheldon’s George Sr dies, Georgie ends up trying to support his mother and his younger siblings, eventually overworking and burning himself out.
Before forgiving Sheldon, Georgie sacrifices his independence, and presumably his relationship with his first wife, to support Mary, Sheldon, and Missy.
Georgie and Mandy are unfortunately doomed to break up because Georgie is divorced by the time he is seen in The Big Bang Theory.
The worst way for season 6 to handle the death of George Sr would be for the show to depict Georgie and Mandy continuing their relationship, having a child together, getting married, and then breaking up because of Georgie’s inability to provide for two families after his father’s death. This is way too dark a storyline for spinoff and would a monster for expecting her son (who already has a child of his own to care for) to look after his siblings. Similarly, Mandy breaking up with Georgie over his inability to handle the loss of his father would be uncharacteristically callous.