I had a company like that. I just ran Windows in a VM and connected it to the company domain controller. While at work, I used x11vnc on one display, tightvnc on the Windows VM on another monitor and would use that with WebEx if I needed to share my screen.

At home, I ran the same setup but I used my gaming/windows laptop for my VNC client and WebEx. I could never get the Linux Cisco VPN client to work, so my work laptop just made an openvpn connection to my flat (fibre connections are nice).