Is protectionism more suited to large economies?
This is partially opinion-based. Even if we were able to calculate all the effects, we can still argue if variant A is better than variant B or vice versa.

I don't think that protectionism is suited to any economy. It typically protects local producers at a cost for local consumers. Local producers have less competition on local market, which allows higher prices or worse products, lower efficiency and so on. The winner is not the nation/state. The winner is just the producer, at expense of consumers.

Considering just relations between two states, protectionism damages both of them. It prevents usage of comparative advantages.

It might look like some big players like USA can more or less ignore rest of the world and produce locally everything they need. Well, they probably can, but at some cost. They can ignore manufacturing in China and build phones locally. Those phones would be quite more expensive and less competitive on both local and global market. They can force some advantage for local vendors on local market (at some cost for local consumers), but this does not help the companies on global market. Even with comparable level of isolation, United States could be richer than, say, North Korea or Iran. But they would be nowhere as rich as they are now. 

By the way, there is some evidence of damages of de facto protectionism in large countries: sanctions on Russia. You might argue this is not protectionism. However, it has quite similar consequences – it inhibits international trade. The reason does not matter, the result seems to be the same.

Maybe it would be more disasterous* for a small country. But I don't think protectionism is useful even for large country.

*) in per-capita metrics