Can I run two DVI screens from one Thunderbolt 3 port?
Yes, you can. Here is what you can do:


Buy the CalDigit Thunderbolt™ Station 2 (Updated CalDigit TS3 Lite Thunderbolt 3 Docking Station)
Buy a simple HDMI --> DVI adapter
Buy a Thunderbolt --> DVI adapter


Now, using one Thunderbolt port, you have added two monitors. The Thunderbolt Station includes a Thunderbolt Port, a HDMI port, and plenty of other things the new Macs dropped (Cough Cough, USB ports).