There are many interpretations and levels of remoteness.
In my case, I want to be away from the sights and sounds and crowds of anything that would be considered urban or suburban. My prime criteria is that I don't want to see another person unless I choose to. I don't want to see a road with cars on it, I don't want to see another house or any other man-made structure that isn't mine. Ideally I don't want to hear anyone else either, but I accept that I may hear things in the distance.
I don't want to be a complete hermit, and I'm not a survivalist looking to be 100% self-sufficient. I want a small-to-midsized town about 30-60 minutes away. Something with a grocery store, gas station, and a post office or other place to receive deliveries. I don't want to be more than an hour away from doctors' offices or a hospital or urgent care. I don't want to be trapped by snow for weeks at a time.
Saying "far from civilization" was a stretch. What I really mean is I don't want to have people all around me. And I don't want to be anywhere near cities and suburban sprawl. I don't want neighbors in any meaningful sense.
Places I'm considering are Maine, Montana, northern Wisconsin, Upper Peninsula Michigan. I would absolutely consider parts of Canada, particularly northern BC. I don't have an easy path to Canadian citizenship, though. Before my Canadian girlfriend passed away last year, we had been planning to look for a secluded lakeside cabin or undeveloped land in BC.
My requirements are dense forest (desert/plains states are right out) and water (lake or canoeable river) on the property itself. I can live with other people using the water, so long as it's not motorboats and a party scene.