My actual speed and accuracy in Colemak is worse than this, though. It takes some steady typing to get into the mode, and in practice I'm starting and stopping all day.
When doing my morning speed tests, I do the Qwerty test, then start typing this forum's post / update in Colemak. I'll even type any extra stuff to include (the after results stuff). After such time, ready or not, I go for the Colemak speed test. Then add any new stuff to the post that might have happened during the test.
It's possible that it's not enough warm up time, I dunno.
Since nearly all of my typos are now Qwerty-isms, or possibly hitting keys out of order / too fast... I just go with it.
You've got two weeks head start on me, and although our speeds are similar - your accuracy is far better than mine.
I'll admit to have done very little coding in Colemak. The closest would be some SQL. Been avoiding C in Colemak so far heh.
I have no idea how long it will take to get used to ; positioning ... most use it gets right now is making emoticons.