http://www.faa.gov/training_testing/testing/airmen/test_standards/media/faa-s-8081-4e.pdf
Refer to the Rating Task Table on the Instrument Rating PTS(Pg 31). You are not required to do a ground portion on an IPC. Neither are you required to do 6 approaches/holds/tracking navaids as part of the flight portion on the IPC. You are only required to do the necessary tasks as given in the table. Of course, it's instructor discretion as to how he wants to do it, but he could sign you off if you show proficiency in the required tasks as mentioned in the PTS. Include an hour of ground as per 61.56 so that you have that covered if you want the IPC to count as a BFR as well.
While the IPC does not require any ground the FAA's IPC Guidance does recommend "...a good
rule of thumb is to plan at least 90 minutes of ground time and at least two hours
of flight time for a solid evaluation of the pilot’s instrument flying knowledge and
skills.
...
A thorough IPC should cover general operating and flight rules for
IFR as set out in 14 CFR Part 91 and in the Aeronautical Information Manual
(AIM).
...
The flight plan should include
consideration of all preflight planning elements required by 14 CFR 91.103, as
well as appropriate instrument departure, arrival, and approach procedures.
...
To ensure a thorough evaluation of the pilot’s weather interpretation and analysis
skills – especially if the weather for the actual IPC is MVFR or better – your own
advance preparation might include obtaining a weather briefing for the assigned
route on an IFR or low IFR (LIFR) day. You can either provide this IFR briefing
to the pilot for advance analysis, or present it during the session for an on-thespot
review and evaluation."
http://www.faa.gov/pilots/training/media/IPC_guidance.pdf
Now granted, nothing does say "...shall...", but if CFI's don't follow the guidance we may find it regulatory in the future.