Heading to the cottage for a week...

When it's warm, I gravitate toward chilled or room-temperature foods. I'm thinking salads, salads, salads! Pasta salad can accommodate almost any add-in, from veggies to cheese chunks to hardboiled eggs to beans to leftover grilled meat cut into bite-sized pieces. Also easy to flex up or down depending on how many at the table; need more food? Cook more pasta! Same idea is a big bowl of greens topped with diced veggies and proteins of your choice, your own riff on chef salad or Cobb salad, depending on what you have available. Grain bowls can be light and refreshing.
It can be fun with a crowd to do DIY soft tacos, where you just put out bowls of ingredients and let your guests help themselves; we do the same with Vietnamese-style rice-paper summer rolls.
There are several articles here on Food52 titled, 'How to Make X Without a Recipe' which can help you improvise depending on what's available. Let your ideas be guided by what might be fresh and available near your cottage; what's the local farm stand offering? Are you by the coast where seafood is readily available?
I would suggest you avoid meals that rely on individual pieces (e.g., grilled chicken legs or ears of corn) as it's harder to flex up and down depending on number of guests. If you want hot meals, AJ's suggestion of Carolina BBQ, or lasagne, or dishes like that are more adaptable to crowd size.
Enjoy!

Will you be going there by car with a cooler? My mother managed our beach vacation food involving 12 - 20 people, including many teenagers who seemed to eat constantly while there, for years.
She always made and froze an enormous batch of pulled pork, North Carolina style, a week or two before leaving. Many years she roasted turkeys. And don't forget fried chicken, which is fabulous cold! You could also get a large ham or two - so convenient for sandwiches, also for easy dinners served cold, perhaps with some of that fried chicken and whatever fresh produce you can pick up - corn was a mainstay in our OBX kitchen.
The advantage of freezing the pulled pork is that it helps keep everything else in the cooler nice and cold during the drive down.
Of course, don't forget that a lot of people love deviled eggs, especially when served with ham, cold fried chicken and potato salad.
Have fun! ;o)

I make Ruth Reichl's Painless Pasta for Three alot. You can easily double of triple the dish. You chop some garlic and basil into a half cup of your favorite olive oil. Cut 5 ripe tomatoes, squeeze out seeds, and chop them into the olive oil. Cook a pound of spaghetti, put it in a bowl and mix with the olive oil and a ball of mozarella di bufala that you've cubed. So delicious and effortless.

How many in your crowd?

Orzo or Israeli couscous with pesto ( a great practical cottage ingredient ), olive oil, capers and tomatoes sun-dried or fresh (or both ! ). Add in some feta or fresh herbs.. endlessly customizable, good at any temperature and a definite crowd pleaser.

I will recommend one or two dishes (I figure that others will provide ideas for the rest of the week):

- Pasta with Tomatoes, Basil, & Brie: https://food52.com/recipes/18892-pasta-with-tomatoes-garlic-basil-and-brie
My favorite quick meal that even the picky 2-year old loves. You don't even have to marinate the cheese and tomatoes given time. I've done the assemble after putting the water to boil and it's just as delicious. No hard to find ingredients.

Parmesan-crusted chicken breast:
https://www.justapinch.com/recipes/main-course/chicken/hellmans-parmesan-crusted-chicken.html

Truly crowd-pleasing and simple. Only 4 ingredients & ~20 minutes.

Does "crowd-pleasing" in your question literally mean you're cooking for a crowd (30+) for a week or you want recipes that have been approved & gobbled up by a crowd, or both?
Either way, others have gone before you, made mistakes & learned as professionals (caterers, chefs, managers of take-out stores, cookbook authors) what works & doesnt. Search for crowd recipes from those you know & trust, or even by region, e.g.:
Northeast and Long Island: Martha Stewart, Ina Garten
South: Edna Lewis, Chef Allen Susser in Miami, your favorite in Nashville, New Orleans, Atlanta.
Midwest & west: Pioneer Woman, Sunset Magazine, Deborah Madison, Alice Waters, Michael Symon, Mike and Amy Mills (for barbecue).
On this site: many hotline threads on planning dinners, menus, cooking for a crowd
Off this site, but related: look at A New Way to Dinner (by founders Stubbs & Hesser) which has four week-long summer plans, including shopping lists. Mains range from basic pork chops and meatball subs to fancier Thai Steak salad and seafood dishes, but most ingredients available in most stores. For a family of 4 but you make larger versions for your cottage house-party.
Off this site: various websites have plans, including quantities for cooking for 30, for 100, for 150.
Hope these ideas help...