First shorten that url. There are a lot of different shorten service out there. In most of time, those service provide consistent url length which is also good.
You could write small app for that to generate massive amount of shortened url. Shorten as shorten url include user id as whole not just your site url.
Once url is short, amount of code cell should decrease a lot. Generate one and give it a try, record how many cell per each side.
Level 1 Code. holds 17~25 characters (alpha numeric or acs ii) 7~10 with high error correction
Level 2 Code. holds 32~43 characters (alpha numeric or acs ii) 14~20 with high error correction
Here is a shortened url: http://goo.gl/xwCNC
19 characters. Level 2 code with medium to high correction, or level 3 code will do.
Choose iso-8859-1 character encode, quality H with shortened url. It is about 29x29 cells, quality Q is 25x25 cells.
For quality H. better size will be 29x29 or 58x58.
For quality Q. better size will be 25x25 or 50x50
Above are all with outside border set to zero cells. If add border, it will of course require larger size. But in most case, when you print on something, you won't print code's edge to target's edge anyway. So ignore border sometime is alright.
This should give you some idea how you should do it. Shorten URL is KEY. With your above url it will be too long to make it easy to read.