A few months ago, I found that Registax can make images larger than the frame by overlapping frames. It stores the frames in RAM while working on them. (Late at night while working I noticed the hard drive wasn’t making any noise.)
I set up the telescope one night, and found the batteries were dead, so it could not track. Conditions were too good not to take pictures, so I let the moon drift across the field of view while recording. Back inside, I converted the video to individual bitmap frames, and let Registax work on a few hundred at a time. Four or five images would be the result from about 1500 to 2000 frames, with generous overlap. Saving as bmp, I’d open them in Photoshop for final adjustment, cropping and saving for web, to produce jpegs. Software available from http://www.autostitch.net will let you assemble a set of jpegs into a panorama. Here is one result. Prominent is Sinus Iridium, the bay; Plato, the round crater, and half of Mare Imbrium. See the Sinus Iridium page for a full-size image.