Thank you very much to all for your input. It seems I was able to do what I was intending on using a completely different method.
I applied a fixed height to the wrapper div. Then displayed the sidebar div as a table and the body div as a table-row. As soon as I applied 100% height on both, viola! The sidebar div came straight down to the footer, occupying the height of the wrapper. To test it, I increased the height of the wrapper and the sidebar div followed
I just hope this method doesn't have any serious rendering issues in the different browsers.
I guess we can mark this thread as closed and resolved!