Okay, it seems I now have the stupid questions' day.
I wonder, once there is support for _far code memory access in avr-libc (pgmspace.h and stuff), why did not GET_FAR_ADDRESS - of the very same author, Carlos Lamas - make it to the same library?
It took me quite some time to dig it out off this forum and other places. I believe I am not the only one using AVRs with >64kB FLASH. There were at least 3 official releases of WinAVR since Carlos published GET_FAR_ADDRESS.
What am I missing here?