My crafting writ level has started having me make deliveries to Craglorn. Through this I ended up with Woodworking and Blacksmithing surveys. I ventured out to harvest the surveys.

I noted the enemies were lower level than I was. I am CP 130 and the ones I saw were CP 110. Still if attacked I am killed off typically in a matter of seconds. I know Craglorn is focused on group questing. I had been there before by group invite and explored just a little but gave up (I had just reached champion ranks).

I am assuming then that the whole of Craglorn works like a giant group dungeon and isn't designed to be survivable solo.
Are the enemies outside the dungeon scaled or fixed? If a level 50 player can access Craglorn I would assume their survival would be even more hopeless, unless there is some scaling involved.

How many people at what kind of level are required to make the zone reasonably survivable?
Is it ever survivable for a single player or will the difficulty keep scaling to match my player?

I did see the odd player who seemed to be on their own in Craglorn. I don't know if like me they are trying to get around avoiding any mobs in order to survive.
There are certainly rich rewards there (I ended up finding my first Fortified Necrux) but that might be negated by the cost of repairing my gear if I keep dying when I get too close to any mobs.