Without a dedicated video card, it’s going to be tough. CPU and RAM meet minimum requirements, but the onboard Iris card will be a major bottleneck. Native MXF from the camera would probably benefit from converting to something else to reduce the load, but that’s a band-aid on a bigger wound I’m afraid.
Complexity of your timeline will always be an issue as well.
I haven’t personally worked with external GPU’s as of yet. But I do know people working with RED footage who offload that heavy lifting to an external box.
The good news, we can always work smarter. Hardware shouldn’t be a limitation unless you’re working for time / speed on deadline. Premiere is so much better at handling Proxy workflows now, the only major downside is taking the time to convert everything, which I personally welcome in the age of how fast can we produce stuff. Gives me time to organize and put things away properly.