I forgot to mention, it's Endless Summer.

Is this plant indoors or out? Can't tell from the photo.

If outdoors, I would consider that appearance somewhat normal for December, depending on exactly where in zone 8 you are located. If indoors, there could be several reasons it looks this way but they would all be cultural rather than pathogenic.

It was outdoors until we moved about a week and a half ago, and our new place has rules against having dead plants on the balcony. I'm sure the management can't discern between a dormant hydrangea and a dead one, so I brought it inside for the time being. Could that have affected it? The soil isn't soggy and I've been spraying it with neem oil to keep the bugs out.

Do you have a friend who could 'foster' your hydrangea outdoors until it leafs out again?

I don't think you are going to find indoors over winter will work for you - it will be much healthier given a dormant winter period and will struggle with indoor lighting, temperature, humidity.

It's already started to bud! I think being brought inside tricked it into thinking it was spring. If I give it to someone, will the buds die and keep the plant from flowering next year?
It is by the window, and the temperature in this new place is really stable and it's not humid. Is that still bad for it?

Your leaves look like most hydrangea leaves look after a full season. They get this look that says 'fungal infection" and change leaf colors. Since it is late in the growing season, I would not bother applying fungicides. But I would dispose of all dried out leaves in the trash.
The 'not humid' part in your statement above would be a problem since hydrangeas in "growth" mode prefer some humidity and the insides of homes tends to be very dry during the winter months.

And yes, bringing it inside looks like it woke it up.

I would touch base with the people at the place where you live to make sure that they know this shrub is dormant, not dead. Then I would put a note saying "dormant hydrangea shrub" on the plant somewhere and then I would put it back outside so it goes dormant again and does not try to bloom (you will get new leaves later). While you are at it, check the soil moisture now and then to make sure it does not dry out.

Have a Happy New Year, supaacupid!

The sign is a good idea! However, my balcony has west-south exposure. Could too much sun ruin it?

If the cold kills the buds that have appeared, will they grow back in the spring?

Q. Could too much sun ruin it?

Not during the winter or spring. During the summer, you could have a problem if you live in the South where the sun scorches the leaves. So if you live in the South, provide some afternoon shade. If you live in the northern half of the country then you could "test the waters" during the summer. Observe if the leaves stay green or if they turn completely yellow/white-ish, including the leaf veins. If you see the leaves turning yellow/white (only the leaves in direct contact with the sun) then move the shrub elsewhere or provide shade starting somewhere around 11am-1pm. Too much sun can also cause the soil to dry out quickly so make sure you mulch and add water when a finger feels almost dry or dry when inserted to a depth of 4".

Q. Will buds grow back in the spring?

Yes, the buds will grow back. By the way, feel free to bring the container indoors for a day or so when extremely cold temps are announced.

I have one plant that was conned into starting to leaf out before the temperatures dropped considerably Xmas Eve. The leaves stopped leafing out but those 1/8" tiny leaves will get zapped next week when we get hit by single digits.

Luis

Thanks for all the help! I also live in zone 8, so I'm sure the summer will be too harsh on it, so i'll give it some shade. :)