How To Access VM When Mac Has No Internet Connection

I run an Oracle Primavera P6 EPPM system on a Windows 10 VM, and the web interface of this system runs on a Fusion Middleware Weblogic server. My SQL server also runs on this VM. Everything works great when my Mac is connected to my home network; the Windows VM has a static IP, and is configured to run in Bridged Mode. I prefer to access my P6 system via Safari on my Mac or iPad. The URL for the web portal is <VM_Name>:<Port>/P6/Action/Login. My Mac OS X Server (Mavericks) is my house's DNS server. I have all Ubiquiti network gear, and am running a Ubiquiti Dream Machine Pro as the router and controller.

So I wanted to test what happens if I don't have network access on the Mac: like if I'm on an airplane and still want to access P6 web portal from my Mac. Turning WiFi off on the Mac breaks everything. The website can't be found. I've tried Shared Mode with port forwarding on, but can't figure out how to access the website running on the VM. I tried to access the website from Firefox on the VM using the original URL with the box's name, but since there's no DNS server available it can't resolve the name. So using 'localhost' instead worked on Firefox on the VM. But no go trying to get to the website from Safari on my Mac. I have also tried entering the Shared Mode IP address, etc., but no go.

Does anyone have any advice on how to set this up so it'll work when I'm not on the home network?