Making The Switch

I recently watched the 1978 remake of Invasion Of The Body Snatchers. It was better than I remembered. (It wasn't really a hit in its day, and aside from Pauline Kael, who raved, the critics didn't think that much of it.)

But I still have a question. The mechanism by which bodies are snatched is very unclear. There are all these plants and spores from outer space that latch on to you while you sleep. They apparently take your brain, or essence, and create a new alien body that still has your memories, while your old body is destroyed. This is already tricky enough. But what I don't get is how close do the plants have to be to get to you? It sometimes seems, such as when Brooke Adams gets replaced near the end, that anywhere in general where the aliens are is enough. But then we see Veronica Cartwright living among the aliens and not changing--she can't stay awake forever, how does she manage?