Hey would anyone like to venture an opinion? :-)

Would this card:

GeForce GTX 1660 SUPER GAMING X 6GB PCI-E w/ HDMI, Triple DP (PCIe 3.0)

likely work with this motherboard?

ASUS M4A88T-M (PCIe 2.0)

I'm looking for a solution to bump up the graphics on this PC for temporary use (i.e. next year or so).

Yes, it will work. PCIe 3.0 cards are backwards compatible.

We could nerd about the PCIe 3.0 vs 2.0 bandwidth limits and if this card would ever go past that and so on, but it is pointless in your case. You will be limited by any processor this board can support *waaaaaaaaaaaaaaaaay* before you hit any limits on that GPU.

Kind regards,

-- 
Alberto Abrao
204-202-1778 (Landline)
204-558-6886 (Mobile)
alberto@abrao.net