[rcheshire (Rowland)]

If you are not guiding, it's easy enough but tedious to dither using your hand controller buttons. My hand controller is set to the "lowest, high speed response," if that makes sense. I find this shifts the RA and DEC axii, just the right amount.
I've posted this before to give an idea of what I mean - not the only solution by any means, but easy enough. This pattern keeps the object within the FOV as you progressively dither between images. Every second or third image will probably do.

EDIT: Using the best quality sub as the stacking reference image may alleviate the problem as well. At the end of the day, temperature matching darks will improve things substantially. In the early days I would wait for a night of similar conditions and shoot a new bunch of darks.