The Enterprise is delivering VMF 211 to Wake Island.
.
Locations Of Warships Of The United States Navy
December 7 1941
Aircraft Carriers (7 + 1 Escort Carrier)
Hull #Vessel NameLocationFleetCV - 2LexingtonAt sea transporting aircraft to Midway Island.
460 Miles East of Midway.PacificCV - 3SaratogaAt San Diego California.PacificCV - 4RangerAt sea returning to Norfolk Va. Caribbean.AtlanticCV - 5YorktownAt Norfolk Va. AtlanticCV - 6EnterpriseAt sea returning to Pearl Harbor from Wake Island.
200 Miles West Of Pearl Harbor.PacificCV - 7WaspGrassy Bay Bermuda. AtlanticCV - 8HornetFitting out Norfolk Virginia. AtlanticAVG - 1Long IslandNorfolk Virginia. Atlantic
http://www.navsource.org/Naval/usf01.htm
The BEST the IJN could hope for was getting the
Lex & Enterprise in port. Realistically only
Enterprise was in any real danger of making port since
Lexington was outbound to Midway with VMSB-231 and its Vindicators. The carriers were running all over the Pacific ferrying penny packets of aircraft (and keeping an eye on the expected Japanese line of approach for ANY sort of attack against Hawaii out of the Mandates).
As far as the original question... Almost no difference.
The Pacific Fleet would be reduced to two decks until the
Yorktown reached San Diego on 12/30/41 (IOTL the Pac Fleet wound up with two decks anyway because the
Sara was torpedoed on 1/11/42 while moving to meet up with
Enterprise and had to return to to Bremerton, via Oahu for repairs. This attack almost certainly doesn't occur if the
Saratoga isn't rushing to jion up with
Enterprise.)
Carriers at Pearl or not, Japan gets hammered flat.