Cold conditioning Altbier - need some sage advice

I apologize in advance for my newbness. I've searched around quite a bit on this topic, but since it's a bit controvertial, it's been hard to arrive at a firm answer.

I've got a high-gravity altbier (1.067 due to my idiocy in undershooting my volume and not topping off) that's been in the primary for nearly 2 weeks now. As of Monday the gravity was at 1.020, but there was still a slight amount of activity, so I've been letting it sit and finish up. I'm going to take gravity readings every few days until I'm sure that fermentation is complete.

Once fermentation is complete, I'm going to cold condition it at 40deg - 41deg for 2 - 3 weeks so this WY1007 yeast will hopefully flocc out and the beer can smooth out. There is a small amount of trub on the bottom of the primary. Given the timelines involved, the presence of some trub, and my lower volume (~4 gallons), should I go ahead and leave it in the primary, or would you fine fellows recommend I transfer to a secondary. I'm hesitant to transfer simply because of the potential for oxidation due to the additional head space that I would have thanks to my lower volume.

Kaiser has a thread or two on making alt. Worth the search.

My advise would be to rack it and condition one month at 50 deg.