Hey @captcrunch, welcome to Computer Forums 
I would say it all depends on exactly what sort of work you’re doing from home. If it’s basic non macro spreadsheets then Libreoffice (which most people now use in leiu of OpenOffice) is a good bet. I will be honest it doesn’t feel as polished as Microsoft Office but you can’t beat the price of free.
If you do any sort of macro work or use spreadsheets that depend on them then I would say you would most likely want to continue with 365.
Do you use Outlook for email? Libreoffice doesn’t offer any sort of alternative and this is often part of the MS Office Suite.
If you are using your office computer remotely then perhaps you can avoid buying Office again at least for now until if/when things go back to normal.
An alternative that is supposed to be more compatible with MS Office is SoftMaker FreeOffice - though it’s not open source so not sure how much I can trust it having never used it myself, it does appear to be a legitimate alternative that is also free.