Everything that the others suggested works nicely enough, so if you prefer to stay vanilla, I would do that.

If you prefer to just mod the game, then I really like Any Portal ( https://www.nexusmods.com/valheim/mods/170 ) and it would be exactly what you want to do.

So you can name one Main Base and link all outside portals to it. And then you can either switch where the Main Base portal takes you each time from the drop-down menu, or you can set up multiple portals.

I don't think they will include such a feature in the base game since that removes some of the struggle, but if not, I'm sure a mod for it would always exist