The problems with the Allison engines of the early P38s in the ETO are well known (either due to fuel, intercoolers or other reasons), but were the P38s in the Aleutians having any of the same problems? These were early P38 models and in a cold theatre of war.
Actually there is a large amount of confusion about the
early P-38s in the ETO compared to other theaters.
The
Early P-38s (E's and F's) only did a few missions in the ETO in Sep, Oct of 1942 before they were all sent to North Africa during operation Torch. Aside from a few recon planes(?) and group of plane in Iceland, the P-38 would not return to the ETO (or at least England) until the fall of 1943 almost one full year. When they did I believe it was with P-38H aircraft, could be wrong. There may have been some G's. However P-38Js soon showed up and that is the plane that trouble with intercoolers, at least withover cooling, early planes didn't have enough intercooler capacity for the higher powered engines.
The P-38s in the Aleutians didn't fly at high altitudes for long periods of time. The Aleutians aren't quite as cold as many people believe. The Japanese currant (similar to the Gulf stream)
Helps keep the Aleutians somewhat warm or at least above sub zero most of the time.
Modern weather for Dutch Harbor
"Over the course of the year, the temperature typically varies from
31°F to
57°F and is rarely below
22°F or above
63°F. "
Not saying it was pleasant. Damp and cold or damp and cool seem to the be the two choices

but it was not as cold as Europe got some years in WW II.