What to wear to the horse races?

My company (the owner will be there too) has invited the employees to the horse races this coming Sunday. I've been to the track once before with my family like 5 or 6 years ago. The only thing I remember is that it was hot and I lost $$$.

I'm used to dressing up very nicely for work in a professional setting so I don't want to be too terribly casual for this event but not over-dressed either. It will be hot for sure but I don't want to wear any kind of shorts or cropped pants. I hate them and don't own any. If I wear pants they will need to be long pants. Also, I don't wear skinny jeans. I'm 37.

I have a few ideas in mind.

1. A summery knee-length dress, bare legs (normally wear hose to work), and flat sandals. I have high heeled sandals too about 4 inches I can wear if you think that's better. I will be getting a pedi before going of course.

2. a lightweight striped color-block top with pink, white and orange diagnal stripes (very cool), light blue American Eagle flare leg jeans and 3 inch pink wedge flip flops (because my jeans are way too long for flats but will probably drag the ground anyway).

3. a solid dark blue tank with some new blue/white patterned palazzo pants and white 5 inch platform high heeled sandals. I have to wear heels with these pants.

4. a white cap sleeve tee, black flare leg yoga pants and black platform wedge flip flops.

Finally, the same white tee as above but with a short bodycon knit skirt mid thigh, bare legs and the same black wedge flip flops from above.

Opinions or suggestions for changing these outfits are welcome or creating a new one or pick an outfit from above. Please no rude answers and stay on topic. Thanks! I always choose a best answer so your time will not be waisted I promise :-)