i found a couple vendors implying 2x32gb compatibility, one selling a 2x32gb ram kit ('guaranteed compatible' they say) and the other selling the pc itself (oos, though) with 64gb, for this model even though its published specs say 2x16gb max. so it might just be possible, depending on the specs of the memory modules.

buy one kit first from a vendor with a reasonable return policy and try. that's all you can really do.