There is a potential risk if the port is a default/commonly known for the webcam.
I would advise that you:
a) Attempt to change the default port used - This will prevent bots brute forcing commonly used ports to connect to the camera. Do not use another commonly used port. Wikipedia has a list here.
b) Ensure any user name and password used is strong using a mix of uppercase, lowercase, special characters and numbers as well as not using common phrases or words. A bad password is Password1!
. A good password may be k3Yb04Rd!nG&
.
c) Create a VPN (Virtual Private Network) which allows remote devices to effectively join the home network from a external connection. The connection will be encrypted and has the added benefit of having full access to other network resources (such as the printers you mentioned). From this, you should be able to access the webcam like you are still connected to the home network. Some routers do provide this functionality (if you list your BT Hub version, it would be useful (I can't post comments to tell you this)). There are various different encryption types with OpenVPN being fairly commonly used and documented.
d) Not a ideal solution as it still involves opening ports but I will mention anyway. You can open the remote desktop ports and allow remote desktop to a PC instead. From there, you can view the webcam through your desktop browser. As said, this is not ideal but may kill two birds with one stone if you are intending to also set up remote desktop at some point. You can also change the default ports in this system (in relation to point a) and will still need strong passwords (in relation to point b)
Also you will have issues accessing the device remotely if your ISP provides a dynamic IP address (i.e. It will change every so often). This is something you will need to bear in mind when accessing the device. Static IPs are not commonly handed out to home consumers however Dynamic DNS is a solution to this.
Alternatively, you can just check your IP every so often. You can do this in Google by searching What is my IP
but you must do this inside the local network (at home essentially).