How to update a remote branch / checkout?

I'm mirroring the chromium subversion trunk (damn that SVN is HUGE) on my linux laptop, but bazaar would so often OOM. So I started out with a workaround by firing up this on a server with 32G mem:
$ bzr co http://src.chromium.org/svn/trunk bzr+ssh://jesse@jesse-laptop/home/jesse/c2/svnco -v
however, branch/checkout seems to be the only bazaar commands that supports a "where to" argument.
To avoid the huge tree I created a bound branch locally without a working tree.
What I'm trying to do after that is to issue "pull" on my local checkout and it would most often succeed. However I'm really frustrated by the fact that
a) "pull" doesn't support a "where to" argument
b) "update" requires a working tree.

Now that after a few days lagging behind, bazaar would OOM me again on just pulling new changes from Chromium's SVN repo, and now I don't seem to have a way to utilize the 32G server to _incrementally_ update my local branch?
Is there another way other than starting over from bzr co http://svn bzr+ssh://jesse-laptop/somerepo/svn again?

Thanks! Wish you all a merry Christmas