Since this is the Switch community maybe this is a dumb question, but wouldn’t a Steam Deck suit your needs a bit better?
As to not be completely useless; I get about 2-3 hours on my Switch when not docked. Haven’t spent a lot of time in Civ or Skyrim though, particularly not undocked, so I can’t say for sure there, but I’d assume around 2 hours at least, provided the battery is still good.