The North Face - Mountain 25

The Mountain 25 is an actual 4 season. If you truly need a tent for winter camping and expect heavy snow and harsh winds, go with that one.

I was thinking the tent is 82 inch long. I could sleep in it, but I would be more comfortably laying in a larger tent. I have a North Face tent that I thought was a great find, just to find out it's so tiny inside it annoys me (I think it is only around 80"). I would rather pitch a tarp and sleep in my bivy sack underneath.

I didn’t know tents still came with fibreglass poles, I haven’t had one with them since the 80s. The three I’ve bought since then (North Face, MEC, Eureka) have all been aluminum. You could probably just replace the poles of your current tent if you like the tent enough.

Theoretically, you can winter camp in just about anything, it really just depends on how extreme the weather you're expecting to be. If you're camped up on a mountain ridge with gale force winds and the potential for big snow loads, you need a tent that has lots of poles and a low, round design to keep it from getting crushed. So for that, you really want the Mountain 25 (I have one from 20 years ago).

Honestly you just need something with a fly. We’ve had a North Face, and Coleman and a McKinley all with fly’s and all have been perfectly fine riding out rainstorms. A ground sheet/tarp tucked under the tent is never a bad idea either as long as it’s not sticking out catching rain. Set the tent up properly with the guy lines out and you should be good. A vestibule has always been something we have too, one with the full fly not just mesh screens.

Loved my Mountain 25, it kept me dry on some nasty weather days in Scotland

The NF Mountain 25 is kinda trash. Very heavy for what you are getting, quite small inside. I bought one and the pole bent the first time I set it up. If you actually are serious about spending the money necessary to get this type of tent you should consider: 1. Hilleburg tent 2. Big Agnes Battle Mountain 2 or 3 (similar structure to NF but lighter and just as strong from a better and more reputable tent brand). 3. Samaya (extremely light, extremely expensive alpinist level tents)

I used to (10+ years ago) haul an NF Mountain 25. Extremely heavy, yet comfy, and bomb-proof. I did not really go out much in storms, especially since where I was located (central High Andes) everything is above treeline. I'm currently using a Sierra Design Cascade (if i got the name right). It's not as comfy or bombproof as the NF, but is way lighter and more compatible for a do it all tent . I also have tarps for lighter missions. It really boils down to what you want it for. The NF was great for base camping. The Sierra is more friendly for traverses, and pretty cheap too. Both are 2 wall, so condensation is not an issue. I would think that being based in the cascades, you would want something where you don't get wet. I think I've slept in the MSR, its light, but extremely tight and delicate.

I’ve owned a lot of tents Eureka, Kelly, North Face, Big Agnes, REI and our last two have been Core (big and cheap) tents. Only one of my tents has ever leaked even with significant rain and thunderstorms.  Make sure things are not pushing on the wall of the tent and properly stake out your tent and fly.   Others have pointed out getting a better tent will help, and it will but if you have stuff pushing on the wall or you don’t stake it out, they will leak too.   Pay attention to how you are storing your tent too.  I had a wonderful North Face tent that got moldy and after that, the waterproofing was shot.  Water literally pouring in the tent as a thunderstorm roared over Lake Superior.  This was the only tent I ever had that leaked and it was an entirely my fault.  

The Mountain 25 is a legit alpine tent, how much snow and rain are you expecting?