Either way would work. Except -- I now see mention of a well. Would you be refilling from a well? Sometimes that creates another whole host of problems as many wells have metals in them.

Yes, you would have to keep FC higher if you run a high CYA pool, but overall, it might not be that much more bleach because high CYA/ high FC pools don't have to have LC added as often. So, it kind of balances out. Sometimes, CYA goes away over the winter, sometimes it doesn't. You might decide not to do the partial drain and refill and just see what happens with this pool over the winter.

Either way is fine. Just a matter of preference.

If you decide not to partially drain, then continue testing and adding LC to get back to 25ppm as many times per day as you can. You'll continue to do this until you can go from sundown one evening til within 2 hours of sunup the next morning without losing more than 1ppm of cl. At that point, keep the cl high for one additional day for added insurance and then you can let it drift down and then keep it between 8-15 ALL the time so you won't get another algae bloom.

If you decide to go ahead and partially drain, go ahead. No sense wasting LC and thus money that you'll then be throwing out. Once you refill, you'll test the CYA to see where you are with it then, and follow the Best Guess table for shock levels. And, as in the previous paragraph I wrote, you'll test as frequently as you can and add LC to get back to shock level until you can pass the overnight test.

Hope this helps.