Its hard to say, if you can build bigger go for it, if its what the property allows you to have, then it will be more than enough and you will learn to work round it as it seems a bit tiny. But this depends what work you are doing, I was in a similar garage to this round a friends house in size, his was twice the length but jammed with crap. However what I did was to create more front or rear room for when working on the car I would either drive half the front/back into the garage or push it in that much. This kept the elements at bay whilst working on the car and still left me with plenty of room to work on that particular side. Yes it would of been better if you could shut the garage door, but beggars can't be choosers. Also it throws the idea of working on the side of the car completely out the windows, I had to drive the car back out to undo things like the arch guards on the front wheels on a mk4 for taking the bumper off as there's just not enough room on either side.
