Really? Can you hold off leveling up and still win against those high leveled foes?
Depends on your definition of win. If that requires roflstomping the bejeezus out of everything, no. But my goal was just to get to Blackreach. And then to get through it to grab the scroll. I did kill, but found out that even on Adept the falmer (particularly the gloomlurkers and the like) were a bit over my head. And I just double checked the older saves to that point. My level was 3 when I entered Blackreach. I remember I was level 2 through the dwemer guardian parts of Alftand, but I recall struggling with the decision to take at least the two perks necessary to dual cast fury after several deaths in some of the tighter quarters falmer areas.
Idealy, I wanted an 81 character with no perks spent (well, a 15, but holding all the xp of 100 skills) that could be built in any fashion. But with stealth alone, I was really struggling and figured two perks would make little difference and was worth it, so I had to level up once to get a second perk and spend on novice and dual-cast in illusion. With the ability to set them fighting each other to the death, I was able to make it past some tough spots. I could have leveled up as high as 6 or 7 along the way, but I wanted to be as low level as I could entering Blackreach. I don't know what it's minimum level is, but it is the longest stretch of the journey to your final destiny, and I wanted to ensure it set it's level when I entered as low as possible. I wound up rushing in a mad dash past almost a whole tribes worth of them in the last part that leads to the door into Blackreach. The moment I was inside, I spent all my saved level ups and was level 9. Gave myself some more stamina to sprint longer and a bit more magic and the rest in health.
My biggest annoyance was not having nightvision. I wanted a base character with as many options as possible and so didn't become a vampire like I do most of the time. What really was impossible was doing Liar's Retreat at a level 15 boosted by smithing (in Riverwood ironically enough) but still only two perks spent and almost no decent gear. It's about as fun as pulling teeth, but by god I got it. My save. Presuming that saves from older updated versions will be compatible (the reverse is not true).