Poinsettia with root rot, anything else I can do?

My mom bought a couple poinsettias for Christmas, which came in undrained pots, and after being overwatered and kept outside in frigid weather, one of them developed severe root rot. The other showed signs of stress (a few wilted/dropped leaves at the bottom) but otherwise seems to be OK. I rescued and repotted both in drained ceramic pots. For the one wit severe root rot, I removed all the soil and as many dead roots as I could. Luckily, the main thick parts of the roots were unaffected, so that's basically what it has left (not much). I planted it in cactus mix with about 30% perlite mixed in - my main interest right now is drainage rather than nutrition. The plants are have been outside in the sun all day, and I've just brought them inside for the night since we've been having nightly temperatures in the mid-30s or so. I figure keeping the plants warmer and drier will give them the best chance of recovery. Is there anything else I can do?

As you can see, the one on the right is not a happy camper.

I would maybe be tempted to cut back the right one to half and just keep the soil moist. Maybe the left one too actually. Normally this isn't done until spring. Let other comment before doing anything though to see if they have other ideas.

when they are under stress, it is better to keep them in part shade and not sun. i think i would have gone with clay pots as opposed to ceramic since clay will dry out so much faster. i'd just mist them, not water them for a while...let the roots get adjusted.

Thanks for the replies! So keep them inside then? They'll get a couple hours of direct sun in the morning and bright shade after that. I've been putting them outside because it warms them up a lot, and I figure the warmth would be good for these tropicals while they're trying to heal. Sitting outside in the sun, their soil will heat up to what feels like about 80 degrees and also dry faster. When the plants are inside they're going to be at a constant cooler temperature of 60-65 degrees day and night. Is that an acceptable trade off? I'm keeping their soil just very slightly moist for now, the one with a lot of perlite dries out especially fast.

They are tropical so keep between 60 degrees F. and higher