My family did a combination of both in March, and it was fine. The main thing is making sure that everyone is linked together in advance, and each person is only listed once.
I don't expect my husband to ever have his own
MDE account. My parents each have their own, and its more trouble than its worth. My Mom is never going to log into her account during a trip, neither is my husband.
I think my sister made her 14 yo his own, which is ridiculous, because he's nonverbal. I think she just got overexcited, but it meant she had to log in to a second account in order to approve every single connection. There were 19 people in play in March (originally) so there was a lot of mucking it all out before the trip.
In any case, just make sure everyone is only listed once, and all their "reservations" are linked to the same account. You can call (or maybe even do a chat) to get it sorted, if it gets mucked up, but it's easier to do everything "right" the first time.