What would the dress code be?

[SunnySomer]

I've been invited to a "summer ball" (in June, so have masses of thinking time). The last time I went to a ball of any kind I was at university (25 years ago) and I'm now floundering massively when I wonder what to wear.
It's a corporate event but DH has not worked at the firm long so I don't know any of his colleagues/colleagues' wives or partners to ask what they would normally wear.
Do you reckon long or short? (Could not possibly do short short as I'm too hefty). I'm 5'6" and about a size 12-14 (depending on the shop) and reasonably shaply (somewhere between a pear and an hourglass).
Can anyone advise please??????? TIA!

Is he wearing black tie? If so, I would go floor length. Perhaps have a personal shopping day in John Lewis and try loads of stuff on.

Outfits varied widely at our summer balls. Last one I went to I wore a knee length satin, one shoulder dress in midnight blue. There were lots of ladies in full length dresses and lots looked liked guests at a formal wedding.

Personally I think the dress should be knee length or longer.

I would go long (because I rarely get the chance to wear long dresses!) but I expect lots of women will be in cocktail dresses

Hmm. Very tempted to go long. Perhaps I will go for a personal shopping day. Always have a tendency to get carried away and believe whatever the salesperson tells me! (Very excited by the opportunity tbh, as I live in jeans!)

Middle ground is something with a dipped hem like this. (I don't mean that actual dress, I just found a picture to illustrate what I mean!)

Either is fine, but I would wear long; it just makes it seem dressier and more special to wear a dress that you can't wear at any other time.