Proton plan as a couple (Family or Individual?)

Does anyone that pays for proton also use it with a SO? We've been looking to pay for it but the family plan looks like an overkill for us. The viable alternative is paying for the Mail Plus plan for each of us but we are a bit worried that we won't be able to share calendars.

Would appreciate if someone else has the same use case as us and could share their experiences. Thanks!