Wow! If your cya after dumping half of the water is 110, then it must have been 200 before! CYA of 110 is still high, but if you are extremely diligent about keeping cl levels in range, you can deal with it. (I know you don't want to do a partial drain again. But, if you don't do it again now, I'd suggest doing it next spring.)

You will need to keep your cl level between 8-15 ALL the time and your shock level is going to be 25. Since your cl level is so low right now, I'd suggest going ahead and shocking the pool now. In a pool this size, each quart of 6% bleach will raise the cl by 1ppm. If you can go overnight without losing more than 1ppm of cl, then you can let the cl level drift down but do NOT let it drop below 8. EVER! Or you risk an algae bloom. If you do lose more than 1ppm of cl overnight tonight (from sundown to sunup), then you'll need to shock it again and keep it at that high cl level by testing a couple or three times a day and each time adding enough bleach to get back to 25. Continue this until it holds overnight.

Uhhhh........ CYA does not evaporate, BTW.

Yes, you can use a little alk increaser --- it is just really expensive baking soda. Only a little at a time so you don't overshoot. 80-120 would be a good range. Also, the pH is on the brink of being too low. Add some Borax and try to raise it to around 74.-7.6. Start with about a third of a box of Borax. Again, gradual is better than one big dose that overshoots target.

Glad to be able to help. Repost with any questions and keep us posted how things are going!