Downstream is usually not the issue. Most basic internet plans are at least 15mbps down, which is no problem. Being able to participate in a video conference usually means at least 5mbps up. A lot of cheap internet service only offers 1mbps up. How do you know if Google Hangouts will work where you’re going? Do a test Google Hangout with a person at the place you are going to be! (Hint: If there’s no one on the other end to do this with, the place you’re going is vacation. Enjoy!)
You will also need to be sure that you can, A.) log in to your machine as a local administrator without connecting to the network (this is especially true for Mac users, as Macs do not cache your credentials) and, B.) that you can connect to the VPN from your new location. Not all Internet connections, or routers, are created equal and not all will all you to get on the standard VPN. The Sysadmins have other mechanisms, so talk to them before you discover you can't work remotely. If you discover you can't work remotely, you are on an unplanned vacation.
The built-in camera and microphone on your laptop / monitor suck. The added friction of talking to someone without a headset makes your team members not want to invite you to a hangout, which means you miss communication that you would normally have received.
You need a place that is as distraction-free as your normal work environment. Again, if you don’t know whether this will exist where you’re going, it’s vacation. The kitchen table of an occupied house is not okay. A guest bedroom is okay. A dedicated basement is better. Going to another address entirely is best.
You can't take care of kids and work at the same time. Other domestic responsibilities like pet care or meal preparation should fall under the next heading.
Set standard hours and make sure people know them. If you're not going to be working the hours you normally work, overcommunicate this to your team by posting in chat (ex: "Going to the gym for an hour"). Nothing makes your WFH look like vacation more than chat messages like "Has anyone seen X?" "When is X getting online?" "Can someone else take this bug? X isn't responding." Try not to pop in and out. Work sustained sessions with only a few extended interruptions (e.g., lunch, dog walking, gym, light-saber fight with your nephew).
If you are an employee who spends a reasonable amount of time on the phone, it should be relatively easy for people to get you on the phone and for you to call them. This might require you to contact the sysadmins for phone forwarding.