I have...1684 saves.
Yes...I save ALOT. A habit from when my game would crash randomly every twenty minutes.
But I looked at my save files, and you can indeed go pass 1000; nothing gets overwritten or anything.
I still have that very same habit, developed when I was heavily into Daggerfall

In Skyrim this saving mania has resqued me many a time from a glitch or bug.
Just hit reload, ah, just like old times.
Just today I got stuck in the scenery in Blackreach.
If I wasnt in the habit of saving before entering a cell I would have lost a lot of playtime.
(Because I have disabled all autosaves for faster loading and preventing savegame corruption and bloating.)