Welcome to Colorado! Which county are you in? I have lived in Summit County for a while and work for the state's department of transportation out of the Eisenhower Tunnel. Here is some advice I found that works living at altitude:
1. Dedicated snow tires. Buy a separate set of rims, throw on a set of Nokians (what I use), Blizzaks, whatnot. It'll save you money in the long run swapping them out on your car as well as time, since you will avoid having to take your car to a shop to swap out tires on 1 set of rims. You'll also need the snow-tire traction not only for handling your own car, but avoiding on the road all the out-of-towners and those without snow tires who have very little to no idea how to handle a car in snow -- crashes, rollovers, spin-outs are seen a lot in the snow season by us CDOT folk because of poopty, bald, and/or non-dedicated snow tires.
2. Since you have fogliights, Lamin-X makes a yellow fog light cover film you can trim and place on. They are inexpensive (around $15) but look quality, and the yellow will help you see better in snow storms.
3. Have a clear bra installed on your entire hood, as well as the windshield pillars (on each side of the front window), the front part of the roof that meets the windshield, and the headlight housing. Kirby with Colorado Clear Bra in the Denver area is fantastic and highly regarded. A lot of gravel is thrown on the roads in snow seasons, and that stuff is kicked up into the air and lands on vehicles. The OEM bug deflector looks pretty but is worthless on these roads. On a related note, if you ever find yourself behind a plow, stay back at least 7-8 car lengths because the speed of the gravel kicked out the back will shred your car up; plus, the plows will call Colorado State Patrol and report if you are too close, have your brights on, try to pass, etc. We work very close with CSP, and vice versa.
4. A lift kit would be beneficial if you plan on running on US Forest Service roads. Sounds like you already have a skid plate (you'll want it for the front as well as the transmission, called a mid-plate; Primitive Racing has rally tested their gear and worth checking out if in need), which will also help tremendously if your underside is smashed because many of the trailheads lack cell service. 20mm rear sway bar is too much for running on FS roads; 19mm is what you want. There was a thread earlier today that had several people on it who take their Foresters on these roads and stated 19mm is the way to go. If you're just on paved roads, I'm sure 20mm will be more applicable.
5. Window tint your front windows. It looks like you have a sunroof. 3M Crystalline CR-40 is installed on my sunroof glass and has been one of the best add-ons -- the heat allowed through is slight and allows me to have the cover off the sunroof year round. Because I'm that much closer to the sun, I also wax my car 2x a year.
6. If you need a solid shop for maintenance, SubieSmith in Lakewood (Denver area) is solid. Great group of guys. For mods, I have used Simply Subarus in Arvada (Denver area); Dave is kick-donkey and will give you all you need to know about Subie mods. For warranty work, Auto Nation West in Golden has been excellent; Ben in the service department has been my go-to guy. I'd be more than happy to hand over his number.
7. For hoarfrost on your windows, which you will experience regularly living at altitude, the Swedish Ice Scraper is hands down the absolute best for removing it.
8. Avoid having a warm/hot windshield in snow storms, as counter-intuitive as it sounds. In snow storms, this is how I handle them: At home/work, I'll scrape off all the snow and ice, load up the car, start it, and drive off keeping the RPMs below 3k until the blue warm-up light goes out. From the time I start the car and am driving, even with the blue light on, I'll have the defroster on the warmest temp until the inside frost clear out (air won't really be warm yet, just not really freezing). At this point -- and this is important -- I drop the temperature to 68 or so and switch the setting to floor only. If the window starts to fog, I'll temporarily switch the setting to defrost (along with A/C since it is a defogger), let it clear the window, then back down to feet. I avoid at all costs letting the windshield turn warm. I say this because snow falling on a warm windshield will melt on the window and then flash-freezes to the wiper blades, and tons of wiper fluid will be wasted trying, if at all, to clear off the glass. Having a cold windshield allows the snow to hit the glass and fly off. In a typical snow season, I use maybe 1/2 a gallon of fluid -- if that.
All this has worked for me since I live at 8,800'. If you have any questions, feel free to reach out.
