In that we do a lot of east coast camping, we get rained on alot. Depending on the trip is what determines what we carry with us. Like this last trip, we knew we would not be in a single location more than 4 days, so we brought along the 10x10 ezup canopy. On top of that I put a 12x12 white plastic tarp and secure everything really tight with lawn stakes from HD. The tarp also slides into a slot rail on the back of the trailer. This tarp acts as a complete rain shield on the top and some additional strength in strong winds/rain.
If we know we are going to be in a single location more than 4-5 days (like last Thanksgiving), then we bring a 10x20 large portable canopy. We love that thing and it takes me about 45 minutes to put it up or take it down. While heavier and taking longer to erect than the popup, you just cannot beat the strength or room inside it. The reason for using this canopy instead of the ez up is that it is massively strong and doesn't really take that much longer to put up.

Here is from last T'day. Walls were being used to block the wind. Since then we have cut down the height of the canopy from 6'8 side rail to 5'10" to allow the walls to reach the ground. Floor tarp not being used on that trip as there was essentially no chance of rain that week. We quit bringing the green astroturf rug since after about 10 years of use, it got a bit rough.
We have a set of 10foot long screen walls that work with either top and also a set of poly tarps we cut down to also act as 10 foot long solid walls. Finally, we bring along an old 12x24 grey poly tarp to use as a "floor" under both the camper and/or the extra room. The floor has lots of holes in it, which allow water to escape, and thus it keeps the feet pretty dry in the worst of weather. The screens keep out bugs, but also keep out light rain. If a downpour (or cold weather) we close off the tarp walls, which attach to a ground rope we string around either of the canopies. We carry one of those big, round propane heaters that mount to the top of a 20# tank and if needed we can fire it up to warm up the "outside room". We have had this system up in super powerful storms, like 50-60+mph winds and blinding rain amounts.
Now, if really, really crappy weather, like noisy, beating rain at night and we want to watch a movie but don't want to go inside the camper just yet, we use our minivan as a bad weather living room. We leave the 3rd row seats installed at all times, but never bring the middle row. That gives us reclining seats, tons of leg room and quiet against a raging storm. If my modifications I'm doing this summer work out, we won't even need to do that any more, as I'm hopefully building a system that will turn the platform bed into an adjustable "chaise".
Oh, and I'm adding in a convertible dinette inside the camper. Yes, a 2 person dinette inside a 5x5x10 camper. It actually works too.

Pics to come when finished.
dave