Yeah base versions of Beth TES & Fallout games are a lot more stable than all the extra content. You can even add some mods (within reason) to base versions and the game should still be more stable than complete version.

For Skyrim (and other such games on PC) there are mods you can use to increase performance on lower spec hardware. I believe Fallout 4 is the only such game that is more difficult to mod for lower spec.

I've done some testing with Fallout 3 & NV base games on PS3 (which are the most unstable versions of the game, mainly due to hardware limitations), added a few small mods and it doesn't make them any worse.