We will be staying with our S’s gf’s parents (whom we’ve never met) for a weekend and would like to show our appreciation in some way. Based on S’s description they are wonderful people. My question is what do you get people who have everything? I’m feeling nervous that any gift I can think of won’t measure up. We have more limited means while they are very well off.
Baked goods (if you’re a skilled baker) are always welcome and personal.
What region are you from? Something special from your home area can be fun and a conversation starter.
I am not sure about baked goods…I for one do not eat dessert.
Do they drink wine? What about a nice bottle(few bottles) of champagne? You could have it when you are there.
I would not take multiple bottles. But a nice bottle of wine if you know they drink wine is a good idea.
Make sure they drink. My parents don’t, for religious reasons, and it’s always a little awkward when someone gives them a bottle of wine.
I think a good red and a good white wine would be fine.
I would not do anything baked or that would otherwise be expected to be consumed while you are there, unless you know they really like it.
Flowers could be nice, in addition to a bottle of wine.
A gift certificate to a local place could be a treat.
I would not stress too much. I’m sure they expect nothing, and it truly is the thought that counts.
The best answer is to ask your son about what kinds of consumables they enjoy. He can tell you if they drink wine, love dessert, enjoy flowers on the table, etc. Or if they DON’T indulge in any of those things.
You’ll feel better about bringing it and giving it when you know it’s something they will enjoy.
They are flying so don’t bring any wine. I would bring an item that your area is known for.
I live in Michigan and I will bring a food item from here, usually involves cherries
Definitely ask your kid for help especially regarding food or wine. I have a friend who brings me tea towels from the local historical museum and homemade potholders. (She’s much less well off than me.) If they are nice they won’t mind that you did not spend a lot of money.
My go to gift is a box of Frango mints since we are from Chicago. Anything local to your area is good. A nice bottle of olive oil is also often welcome. What nice is what is fairly expensive for olive oil is not that expensive a gift.
Thank you for the ideas! Good ones in most cases! In this case, they own a vineyard and make olive oil and don’t eat sugar. Lol. My only sweet skill is baking but I’m not doing that. I might take a box of Frango mints though- it is regional and the man might eat sweets. I like the tea towel idea. Hmmm.
I, too, would bring something from your area of the country to theirs - maple syrup, cheese, wine, salt water taffy. If they don’t like wine, there are now stores that sell oil and vinegar, infused or plain. We had exchange students stay with us one summer and they brought lace doilies from their small town which my mother loved. Doesn’t have to be anything big.
You could also go for a coffee table type book about your region, a cookbook from the Junior League with local recipes (and a basket with the ingredients?), an invitation to your home for a special event (concert, hot air balloon fest)
If you are local to Chicago (I’m assuming since you said Frango mints), there are some awesome Chicago themed coasters, tea towels, and even architecture coffee table books. Lots of good local stuff 
I’ll put this out there…if you know they don’t eat sugar…I wouldn’t bring an item that is largely sweet - like mints. That seems awkward and not personal - when you know they don’t eat sugar!
I personally wouldn’t give or want to receive something that screams Chicago - like with the name on the item.
(I mean, if it’s mean, bring me a decorative tin (do they have small ones?) of Garrett’s popcorn and I’ll treat you and your H like a king and queen!) 
‘they own a vineyard, make their own olive oil and don’t eat sugar’. My vote is for flowers or a plant then.
I’d also vote for flowers or a plant and definitely avoid sweets if they don’t eat sugar. I’d also ask if I can take them out to a meal while we are in town or make them a meal, whichever they prefer.
How about a framed photo of S and his GF together? Cheap and easy, and meaningful for all parties involved. And sugar-free!
^I like that.
People who don’t eat sugar scare me. I’d bring some kind of protective device. And a houseplant. No one objects to those.
But if you are flying, well, the TSA just might be that no one, so I’d go for a tea towel. Literally everyone uses those. Get a couple with quaint pictures of your hometown.
This is a token “thanks for having us” gift, so it only has to be well-intentioned, not spot on.
I brought these as a gift once for friends who didn’t eat sugar. Big big hit: Coasters from Chicago’s Art Institute . https://shop.artic.edu/item.aspx?productId=950