The first thing to keep in mind is that if there is no embargo or other U.S action in the Pacific, the Japanese never engage the U.S. or UK. Much as the Navy might want some additional basing to the South the Army is never going to allow a distraction from the war in China. That sort of stops the scenario cold right out of the gate.
However, lets look at the chances of the Reich engaging the U.S.
As noted, the Reich's fleet is, even in its most unlikely configuration, going to be notably weaker than the USN (no matter how fast the KM builds the USN will have a massive head start and what were, by 1942, the most efficient yards the world had ever seen). What has not be noted is that the USN would, in this scenario, be much LARGER than IOTL.
As a brief series of examples - IOTL the U.S. cancelled three Midway class CVA eight Essex long hull CV, failed to complete two Iowa class BB that were partly completed, cancelled five Montana class super BB, four of the loathed Alaska Class CB, fifteen CA (6 Oregon City class, 9 Des Moines class), 17 CL (11 Fargo class, 6 Worcester class), 66 DD (12 Sumner class, 52 Gearing class) and 113 SS (62 Balao class, 51 Tench class) simply because the war was won and there was no enemy left to oppose. The ships cancelled would outnumber the proposed KM in sheer number, much less in quality.
In addition to this, the Western Hemisphere would also undoubtedly host most of the Royal Navy (nice thing about a ship is that it moves, if things are going tits up at Portsmouth, there is always Halifax) along with the Royal Family/British Government in Exile, probably in Ottowa. While small compared to the USN, the RN would actually be pretty much an overmatch for the the Plan Z KM, especially in carriers.
So you have a naval force outnumbered at least 5-1, very likely more than 5:1 in critical areas (don't even look at aircraft, the fully built out Essex and Midway classes would mount ~3,900 combat aircraft, the KM ships might manage 150, this doesn't include the now undamaged pre-war Lexington, Yorktown, and Wasp class ships or the Royal Navy decks) that would have to destroy the Western Hemisphere forces before any sort of landing could even become a fever dream. That doesn't begin to account for the mind numbing number of heavy and medium bombers, land based fighter bombers and land based pure interceptors that would be available to face the KM. IOTL the U.S. produced 10,000 P-38, 9,500 P-39, 15,000 P-51, 3,300 P-63 (if there is one number that demonstrates just how much excess capacity the U.S. had, 3,300 Kingcobras has to be a strong candidate) 13,700 P-40, 15,600 P-47, 7,400 A-20, 2,500 A-26 12,700 B-17, 18,500 B-24, 9.800 B-25, 5,200 B-26, and 3,900 B-29. These would be opposed by the survivors of the 150 KM aircraft that had already faced well over 4,000 carrier aircraft mid-Atlantic (BTW: the actual number of carrier aircraft produced is ~33,000 fighter-bombers, 14,000 dive bombers, and 9,800 torpedo bombers). Now with the changes in this scenario the number of aircraft by type will undoubtedly be different, with more of the later model aircraft and fewer of the pre-war designs, this of course also means that, as an example, rather than facing 7,000 SB2C Helldivers it will be 11,000 AD-1 Skyraiders.
tl;dr: Impossible.