The one thing that will probably save you more time and efforts than anything would be to use Hamachi from LogMeIn. It will create a zero config VPN. You install it in Ubuntu. Download Hamachi and install it, it will require the
sudo apt-get install build-essential lsb
sudo dpkg -i <hamachi.deb file>
Install Hamachi on the other computer that you will be using to access Ubuntu.
Create a network either through Hamachi or LogMeIn's website interface. Join both computers to the newly created network. They will not have a direct tunnel to each other without having to open up any ports on your firewall. Even if your ISP gives you a new IP address, you will still be able to connect to the Ubuntu VM without any reconfigurations.
The other thing to do is to install LogMeIn on your desktop that is hosting the VM. This will allow you to remote into the computer and start the VM if it crashed or if you've forgotten to install it.
I use this setup every day and makes life so much easier.