Juniper will do much better being outdoors all season long. It is not an indoor plant and technically no plant is.

Since it is in a pot it does need some extra consideration and protection. If it is just one plant it is a bit easier to. Find a spot outdoors next to your house. Assuming you have land around your house and not in an apartment. Ideally, north side of the house, close to the foundation, will be best. Again, ideally you do not want a very shaded location either. But something, that gets a lot of indirect bright light. Dig the pot in the soil and cover the surface with some mulch or leaves. Water it about once a month or so. Or better yet, drip a bunch of snow on it when available, Around April, it should start showing signs of waking up. Move it into a sunnier location then and keep it full Sun till next winter.

I kind of glossed over details to keep it succinct. But feel free to ask more questions.

Photosynthesis is a process during which the plant uses CO2 from the air and water from the soil along with little electromagnetic bundles from the sun (photons) to produce the plant's true food - glucose, with oxygen as a byproduct. Respiration can be said to be the opposite of photosynthesis, as it uses oxygen to burn/oxidize the sugar to produce the energy plants need to drive their systems and grow, with carbon dioxide and water as byproducts.

Photosynthesis: 6CO2 + 6H2O –––> C6H12O6 + 6O2

Respiration: C6H12O6 + 6O2 –––> 6CO2 + 6H2O

Warm indoor temperatures and low humidity increase your plant's rate of respiration significantly, while short days and less intense light levels decrease the plant's ability to carry on photosynthesis, which we already know is the source of the plant's true food.

Whenever a plant is using more energy during the respiration phase than it makes during photosynthesis, it is in serious trouble because the disparity between energy production and energy use must be rectified by calling on the plant's energy reserves, which are finite in the same sense that the reserve power in a battery is finite and eventually depleted when called on, which always results in death of the organism unless conditions change enough that the plant is able to make more food/energy than it uses.

The chill of winter slows energy consumption dramatically, which means almost no energy is required to ensure the plant remains viable. In spring, the plant reawakens as temperatures move to the mid-40s, with almost all of the energy it had at the end of autumn. Ideally, the plant would be kept at temperatures between 32-42*F, and watered occasionally as required to keep the root/soil mass from drying completely.

Al