HI @RobbieD,
Additionally, in case you are not using it ,you should probably use discardResponseBodies(will need to search it as I can’t link you inside the table 
) This will significantly reduce the memory k6 allocates for big responses that you don’t need the body of.
For the ones you do need them you can use responseType (same deal … can’t link you to inside the table) on the requests that you need their bodies :).
If you feel adventurous we do have a brand new functionality to be released with the next k6 release (0.26.0) … hopefully next week. Until then you will either need to compile it from the source directly or if using docker to use the latest image tagged as master.
Both me and @ned did some performance testing (1 2) with it and the results are promising. Using my (or similar) approach with webpack means that you also don’t need to rewrite your code (hopefully), but will always be slightly less performant . But still a good first step.
We intend on writing a lot better documentation and I am probably going to work some more on the webpack settings before/around the release, but if you have any questions ask away and we will gladly list you as the first “success story” if it works for you and your up for it 