CK2>EU4>VIC2>HOI4>Stellaris
I know I am.

5234480 Dear lord, I had about 1600 hours in EU4 and only seen 1821 twice. Good luck sir.

5234480
The hours of my life that would be lost... are innumerable.

If you can put together or keep together the HRE in CK2, you can finish up Europe and conquer most or all of the world fairly easily in EUIV. Once that's done, Victoria and HoI could be skimmed through on autopilot to make it to Stellaris.

I've actually got a save in which I conquered virtually all of Europe in CK2. The hard part's already done for me!

5234480

I did see a Stellaris Playthrough of the Roman Empire. I've also done a CK2-EU4 Playthrough of the Roman Empire but never reached Vic2. But like above said Vic and HOI would be easy given you are at a size where you can't be defeated unless you RPed to where you did not blob as much. So something like this is possible. I'll do a Jerusalem Grand Playthrough and try to reach Stellaris.

5351844
Do Luxembourg world conquest