I wonder how large your save games get after 1000+ hours. After 2613 hours? If you are on the PC, Wrye Bash can tell you, and so can Windows Explorer.
The most recent save from my current play-through, at just over 1000 hrs, is 10,862 kb. The final game-play session (as opposed to later experiments) from my previous, first play-through stood at 12,673 kb for roughly 928 hrs played. The discrepancy is likely the result in mod differences. That first play-through I had completed several large quest mods not yet installed this time 'round. "Windfall" and the two "Gates to Aesgaard" come to mind. Plus, I had finished both "Lost Spires" and "Cybiades" last time, which are now installed but not yet begun. I was also nearly done with "Ayleid Steps" last time, but only started in on it this past week and am not very far along. I'd categorize that first play-through as very "quest-centric" whereas this one, while still leaning heavily on quests, concentrates more on my avatar living his life in Cyrodiil, performing many mundane tasks (TEC road patrols, TEC tax collection, Wine deliveries for Tamika, Merchant Guild package deliveries) that don't increase save-game size all that quickly.
-Decrepit-