I'm planning my own homebrew campaign which largely takes place in the Feywild, with some of my own interpretations of the place. But even so, I'd like to know how the Feywild is suppose to function as WOTC written as a basis. I've read up on some books, but have not found these answers unless I just completely overlooked them. So a couple questions about how the crazy Feywild is supposed to function:

1. Weather and seasons. Is the Feywild supposed to have one concise order of seasons? Like I get there's the Summer and Winter Courts, but that doesn't mean like for example the Winter Court is only in a perpetual arctic region, right? Is there still a course of seasons that go through the Feywild? Or is the weather only effected by how the Archfey demands in each individual Domain? Like in one domain it is summer, but one domain adjacent to it is winter all the time. Is that possible or is there still a seasons that effects all domains?

2. Same thing with time. I've heard that time is all screwy in the Feywild. Is this based on how each domain works? 

3. And geography. I get that the Archfeys have pretty much full control over each of their domains. They can shape them to their liking. But for the raw Feywild as a whole, does it have defining geographical features? Like is there a mountain range that is always a mountain range despite how an Archfey shapes it? Or is said range still one if that land is unclaimed by any Archffey?

I hope I'm making sense. I know I'm overcomplicating things. But I really want to fine tune the Feywild as much as possible, and then tweak it here and there in my homebrew version. But like I said, knowing how WOTC intended it to work is a good start.

IMO since there's no official guidelines (with mechanics) about how time and space operate differently in the Feywild from the prime material plane (PMP), it's up to DMs to decide. Personally, when I run the Feywild, I don't include time warping (although I do have my PCs roll for WIS checks to determine memory distortions/loss/etc. when they return to the PMP from the Feywild) And as for space, some (unofficial) lore tells us that the Feywild is supposed to bear some sort of resemblance to the PMP. That is, the size, boundaries, geographic features, etc., of Feywild is supposed to mirror those on the PMP. And we're told that, e.g., a muddy stream on the PMP will appear as a pristine, clear stream in the Feywild. I don't do that. The way I run the Feywild is that it is it's own unique world with it's own unique geography, etc., which I separate into regions governed by the 4 seasons (I found a cool map for this). That said, if you don't like the idea of treating regions of the Feywild thematically as seasons, do something else. Search online for Feywild maps for inspiration. It's DND: find and borrow whatever you find appealing, apply it, and create your own world and campaign. As always, since your PCs will likely not travel across the entire Feywild, focus on just a few areas where you expect/want the PCs to travel, and dig into the details in these areas.

I think that the Feywild is intended to be quite loose with the rules. Some thoughts I would have:

Season - depends on who is currently winning on the political ladder between the summer and winter courts. Perhaps with each winter victory, things get colder, and vice versa.

For time and geography, this is where I have homebrewed my own feywild. The main bulk of it is that the Feywild is made by opinion, and is a reflection of the material plane. So if two populations live on either side of a mountain, and one thinks "This mountain is huge", and the other can see even bigger mountains and thinks "this mountain is small", then the mountain in the Feywild will be different sizes depending on which direction you approach it, and if you climb over it, you might find it an easy ascent, but a colossal descent, or vice versa. Same with lakes - one side of the lake may think it to be huge, whilst the other may be able to see the sea and thinks the lake is small, so from one side it is like an ocean, but when you get to the other side, you can see back across it!

The effects on time then will be depending on where in the world you are. So if you're in an elven city in the feywild, time will go quickly because they are immortal so don't see days as that long. If you're in a halfling village, then time will go quicker.