My parents are celebrating their 50th (!) wedding anniversary this summer and are planning to throw a big party and invite friends and family. I need to find a suitable outfit, and this sort of thing always seems to take longer than you might think, so I've been looking for a month or so and haven't found anything great yet.

It's going to be in July, at their house in the midwest US, likely on the back deck, so mostly outside rather than in a/c. I believe the time is going to be late afternoon into evening. So it will likely be humid and possibly buggy but I still want to look nice and cheerful and summery. They're getting a caterer to do most of the logistics but I'm sure I'll end up hauling chairs around or getting ice or helping people park, so I don't want to do impractical shoes or anything too ornate, which I don't think is necessary anyway.

My first thought is a cheery summer dress, maybe with a fuller skirt because it would be more breathable. I'd love to find something in Ted Baker-esque florals (preferably a little cheaper though). As some of you know I'm a cusp size and tallish, so if it's a misses' brand it needs to run up to a size 16 and not be too short. I have a hard time finding dresses since I'm a pear and bigger on the bottom. I'd like to stay in the $100 range unless it is something amazingly spectacular.