Spitfire
I would say it very much depends on your capacity and your background. I think I could have managed this, but I had done a lot of the work before and had a background in the physical sciences. Some other students I know could probably do so too, but there are others who really could not afford the time.
I would recommend you leave it at least until your first progress test (should be about half way through the syllabus of the first half of the course) and see how you are getting on then. Many students do not work hard enough up to this point, and get rather a shock! If you do well and have had some free time, then consider getting some work.