https://www.gamespot.com/articles/nintendo-switch-online-will-have-shared-family-pla/1100-6458806/

Nintendo has finally unveiled its plans for the Switch online service, complete with cloud saves and some retro games. But what if you own two or three Switches? Nintendo says it will also be offering a family membership, which will allow up to eight accounts on a single membership.

As opposed to a basic membership that's limited to one account, all of the accounts under a family membership can enjoy the benefits, even if they're on different systems. The family plan will cost $35 / £31.49 / AU $55, which is less than the cost of two regular memberships together. You can start creating a family group on May 15 to prepare.