I already had this issue at the end of last winter, I think I am better solve it before the cold starts again:
I spew a lot of smoke and start with very low power in my 2001 VW Golf TDI. Now at 100,000 mi, and no other issues to talk of. In fact the car gets all the boost after it's warmed up. Also it happens sometimes that the engine does not start at first few rotations, I have to crank a second time when really cold outside.
For the record, I still have my original glow plugs, but they measure good resistance. There are no check lights, no computer reporting on this issue. Filters, oil etc. I change on schedule.
Any suggestions what to do?