I’ll throw some mostly retro curveballs. They should all be more than enough playtime to get you to Greece and probably home again.
The Longest Journey - old point and click adventure game with a sci-fi/fantasy between-worlds story and a likable protagonist. You get insane battery life playing this one.
https://www.gog.com/game/the_longest_journey
Free Stars: The Ur-Quan Masters - free release of a 32 year old open world sci-fi adventure. Literally my favorite PC game of all time. It’sa predecessor to games like Mass Effect and Starfield, and the music is incredible. Also a low power demand. This game could run on a toaster.
https://store.steampowered.com/app/2645580/Free_Stars_The_UrQuan_Masters/
Marvel Midnight Suns - part phenomenal tactical card strategy game with superheroes, part relationship simulator where you can go stargazing with Spider-Man. Some reviews were harsh because of the weird combination, but if you appreciate the alternating battle/hobnobbing, it’s a hugely entertaining game. Goes on sale quite a bit.
https://store.steampowered.com/app/368260/Marvels_Midnight_Suns/
System Shock 2 - Another classic. Bioshock was a spiritual successor to this much deeper, scarier, more complex immersive sim FPS. It shares a ton of DNA with Deus Ex as well. Its predecessor, System Shock 1, was recently remade to much acclaim.
https://www.gog.com/en/game/system_shock_2