I always imagine the main camp as a place that's accessible through the Netherese portals. I go to the camp the first time through the portal on the beach, and then I assume that each time I long rest there, it's because I mystically travelled there again. In my mind, the campsite is just a remote place in the wilderness nearby.
Yes, I imagine that my party often uses the portals to get back to camp too, though I do think of it as somewhere that's also in principle walkable from wherever we happen to be even if I never actually see my party walk there. I kind of like the idea that they get there via a portal and that's why we can't find the route on the map, but I feel that all the other camps in other areas might stretch that too far for me. I'll mull it over! I also headcanon the Netherese portals as only connecting to each other rather than as places we can just jump to from anywhere, so generally for my party some (off-screen) trekking would be required either way.
Of course, given the portals it would be perfectly possible to keep the main camp as it is in the EA wilderness and just hop back to it from anywhere on the world map that's close-ish to a portal, and therefore keep it the same throughout the game. But I kind of like the different camp ambiences in different areas we have so far and hope Larian build on that, as well as allow players who aren't keen on the fast travel system to headcanon it away.