I never wear dresses, only trousers...... except on holiday, and then the dresses are ankle length. No worries about showing leg, just nice painted toenails peeping out.
Ebay is great, and pp has suggested Charity Shops though it's a little early yet for them to have summer dresses on sale.
I just looked on the Very site and there are 788 dresses across the range.
Also I quite like M & Co and they often have local stores - totally not expensive.
It depends what you are looking for. Sleeves/no sleeves, calf length, ankle length.
Over the head and down to the ankle. If sleeveless then I sometimes use a very very very lightweight large pretty scarf to drape. Often secured to the dress straps.
I never take really good stuff on holiday.