Mirrored bathroom cabinet wider than vanity - will it look bad?!

[Daffodils23]

We are in middle of bathroom remodel ( not DIY) and I'm finding all the micro decisions quite overwhelming!

We have a wall hung vanity which is 70cm wide, leaving about 20cm between that and side of shower screen. I really wanted a lovely big mirror above it and we already have a nice wall light above where the mirror would be.

However DH is insisting on a big mirrored medicine type cabinet thing instead. Personally I don't like them but I suppose it's his bathroom too and I should really compromise!

Anyway, I want the big mirror effect (to reflect the light) and he wants more storage space so we were looking at a 80cm w by 70cm h cabinet. However this is 10cm wider than our vanity width. My question is would this look weird design wise? Normally you would get one the same width or smaller wouldn't you? We could get a 60cm.width but I think.it would be too small for DH ( and 3 teenage daughters' potions and lotions)

I am probably overthinking and I know it's a privileged problem to have but we have saved up for ages and I don't want to.spend all this money and them hate the bathroom!

Thanks for any advice :-)

Can it be centered over the unit? Or is it starting in a corner, and so will "over hang" on one side?
I think if balanced, it will be fine.

Why would you have a cabinet if you have a vanity with storage? Do you need (and I mean need rather than want really) more storage than the vanity? I'd prefer to make the vanity wider if I could.

I have a cabinet but only because there's no other storage in my bathroom. I guess the only positive is you can get closer to the mirror?

The mirror wouldn't be something I'd want to compromise on if I could avoid it tbh.