I'm not sure why you've only looked at Kubota. There's no doubt you can buy a really nice Kubota ($$$), but if it's the most tractor for under $20K you're looking for, you're looking in the wrong spot.
I've now been a tractor owner for almost 2 years (still a newb). My first tractor was a used JD 955 cab with 33hp with 1800 hrs. I knew nothing about tractors and only looked at the "name brand" tractors. I actually bought my 955 from a Kubota dealer. Like any tractor, and especially any older tractor, I had lots of tinker time to learn how it was all put together and how to fix it. I finally had enough and decided to buy new.
I to looked at Kubota, but I also took the time to research as many other brands as I had local dealers to buy from. This included JD, Landini (now a blue Kioti, but not then), Case, Kioti, Branson etc. I made a list of what specs were important to me in a tractor and put them side by side.
You will find that plowing snow is very much dependent on traction which is much more dependent on weight than hp. The
L3800 is not a very heavy tractor when compared to others in the same class (over 1000 lbs less than a Kioti DK40 for example). The other important factors you might be interested would be total hydraulic flow, loader lift, loader height (if you leave it on while clearing snow, this makes a BIG difference), and PTO hp if you'll be using a snow blower or other attachments.
I live in Ottawa. We can get ALOT of snow. Because my wife told me my new Kioti TBL was my birthday, Christmas, valentines day, fathers day etc present, I haven't bought an inverse snow blower for it YET. In the mean time, I use a back blade for snow, and it works very well, you just can't wait until there's 2 ft of snow on the ground with 3ft drifts. I leave the FEL on the tractor and use it for pilling. This is a very effective and cost effective way to clear snow, it just take a little longer (which makes me happy because I get more seat time). I agree with other posts, a snow blower is really the way to go. I'd also never spend the money on a front plow set up since it will be the same price or more as a blower.
My 30 hp Kioti CK30 is at LEAST twice the tractor that my 33 hp JD 955 was. If I was blinded by brand name and bought a new JD, I would have missed out on a much more capable tractor and paid a little more for it.
Here's the worksheet I developed while shopping once I narrowed my search down a little. I'd seriously suggest you make one of your own and be patient in your purchase. This thing will last your life time if you want it too, so a few extra weeks getting it right now will be more than worth it.