Dress code ‘CHIC’ - help needed desperately

[Onanotherhealthkick]

I have been invited to a party (in 10 days time). Dress code is Chic. I am not a chic person at all and actually am not entirely sure what passes as chic nowadays.
It is going to be in a marquee - dinner and dancing. Age range will probably be about 50s-70s.
I’m 5ft 10, a size 10, sometimes 12 and in my early 50s. I have a pair of pale pink sparkly sandals from Dune but no dress!! Colours that suit me - pinks, purples, teals/warm blues, yellows.
Budget isn’t massive (please no Vinted options as I would like the option of sending clothes back). I like Boden, Seasalt, Adini, M+S for my general every day shopping.
Any links or inspiration would be fantastic.

Mint Velvet have lovely options!

https://mintvelvet.com/products/rust-assym-hem-maxi-dress

https://mintvelvet.com/products/leopard-print-midi-dress

https://mintvelvet.com/products/floral-ruffle-midi-dress

https://mintvelvet.com/products/yellow-floral-halter-dress

Have a look at Crew. They have some lovely dresses and often have 40% off. Some of their shirt style dresses are beautifully shaped and look very elegant without the tie belt, specially on a tallish and slimish person.

I cruise a lot and am familiar with terms such as 'chic' or 'country house chic' and have seen dresses similar to the Crew ones looking very much the part.

That's a sundress!

@Pearlstillsinging It’s got pleats! It’s not an obvious sun dress! It’s long and more of a holiday dress for the evening.