Yes it is supported
I believe your system should have no issues running a single vm but adding some more ram would no hurt.
at this moment hexos requires a minimum of 2 drives per pool but in a future update single drive pools will be supported.
i don't know how long itll take for support to arrive but waiting for support is your most cost effective option
personally i always advocate for fewer but larger drives to save on power costs (it really adds up)
but doing your 2 pool method will be more cost effective
This is an issue a lot of us have. The easiest solution is having 2 machines. If you have another windows machine i would just plug the drives into that and transfer the data over one step at a time
The other solution is renting cloud storage for a month but for that amount of storage, not only is it expensive but itll take a long time uploading and downloading the data.
the arr stack has a backup function but i can't attest to how well it works myself.
also not sure how well plex migration works but they have a support page for it
https://support.plex.tv/articles/201370363-move-an-install-to-another-system/
Make sure any drives you plan to use with hexos are not smr drives. CMR drives are more ideal.