To be truly comfortable, you have to wear what is YOU. Something that layers a bit sound perfect for cool morning and then mildly warm afternoons.
If I’m at a lake house I’m not putting on a skirt or dress unless we are going out! That’s ME. I’d wear an athletic/athleisure outfit that was coordinated - not slouchy. A pair of casual running shoes or athletic sandals (teva, keen) and I’d throw a headband in my curly hair that gets even more curly around the water! Done!
Last December I was doing a load of laundry and kind of did a doubletake as it included short sleeve polos, shorts, jeans, socks (never wear unless cold), and a sweater. Oh yeah, it was in the 80’s for two day and in the 40’s with snow for the rest of the week. Typical Denver weather.
I wear variations on yoga pants, shorter in the summer and longer in the winter. I hate, hate, hate maxi dresses. But only because I’m envious of being too short to wear them.
This is the maxi I have and love (different pattern on skirt):
https://www.modcloth.com/shop/maxi-dresses/overseas-ease-dress-floral-maxi-dress-in-navy/153131.html
Note both the plus and regular size models look good in it!
A-ha-ha-ha! Modcloth now describes it as “a traveler’s dress of choice.” They discovered my secret. 
Shorts and I have a light sweatshirt zip jacket I take off or put on as needed.
I’m tall and fat and look best in maxi dresses. The ones that have a seem right below the chest makes me look wayyyyy skinnier than I am.
My mom and I are both shorts people. We’re both tall with long legs so capris look funny and it’s too hot for long pants of any kind.
You’re going to someone’s lake house? Oh ok, I do that quite a bit and I live in Northern Michigan so it looks like you are having the weather we are having currently.
I pack a pair of sweats or leggings for the morning. A tank and long sleeve pullover. I have shorts for later in the day, mid 70’s when sitting on the dock can get warm. So shorts, a short sleeve shirt and a sweatshirt on top. Right now it’s 66 here. I had errands earlier and wore ankle length white jeans with a elbow sleeve top and brought my jean jacket but I never put it on. It is pretty windy. For lounging in my house I have on boyfriend jeans and a 3/4 sleeve t shirt.
I’d bring a rain jacket, you never know if it’s going to rain and it’s another layer.
For a lake house you never know if it’s in the woods and will be cooler.
I always over pack when I go to my sil’s lake house but I take a lot of workout clothes. Everything is very casual anymore. But if shopping mid 70’s, I’d be prepared with a light jacket and wear shorts. If we were going out to dinner, probably a short dress or tunic with Capri leggings and my jean jacket.
I would not wear a maxi to someone’s lake house. I do have a pair of loose chambray pants that I wear to golf in sometimes. And if you are coming up here, it’s suppose to be a great weekend. Enjoy wherever it is that you are going.
70 degrees and my legs are bare even in Northern Michigan! My legs get covered 3/4 of the way in 60s and not all the way until 50s. But after about 5:30 or so when temps start dropping, I’d probably bring a wrap of some sort. But yes, if I was going to go somewhere the temps were going to drop down into the 50s I’d probably have a pair of pants or some leggings and a wrap of some sort in my overnight bag.
Cropped pants…(these are ankle length, and usually have a little slit at the ankle. Longer than capris…which I hate). Wear with a nice top, and carry a very light weight sweater.
Or…shorts.
Unless it’s really a cold wind, you shouldn’t be cold in shorts when the temps are in the 70’s.
Haven’t read the entire thread so I apologize if anyone suggested these yet. Check out Athleta Midtown ankle pants. They are super comfortable and can be dressed up or down.
http://athleta.gap.com/browse/product.do?pid=297748022&tid=atpn001734&kwid=1&ap=7&gclid=Cj0KEQjwz_TMBRD0jY-RusGilOYBEiQAN-TuFGu1jyVZSgV-eKZGyO0opzzPjl2d73kKuNuxko7zSL8aAgvK8P8HAQ&gclsrc=aw.ds
I like hiking pants for in-between weather. They are much cooler than jeans, but warmer than shorts. Flexible and comfortable.
These are favorites:
https://www.llbean.com/llb/shop/68073?feat=505698-GN3&page=comfort-trail-pants&csp=f