I do have RTX 2080 with 8GB - Unreal crashes already at 21% import? The Max file has only 3 Million Polys.
Any other workaround?
u may try importing scene mesh in parts, not complete altogether. like export 0-250 then 251-500 and so on.
Part of the problem is that it’s not just polygons that can effect a scene’s size: textures, for instance, also have a big impact.
I’d definitely check on the resolution of those materials and the texture maps associated with them; I recall someone once quoting that, for instance, an 8k texture, can quite happily eat up 1GB of VRAM. You don’t need many of those at all to fill an 8GB card 
I didn’t even import any materials or texture maps. Just Datasmith import.