Greater White-Fronted Geese, like many of the geese, has a long and confusing taxonomic history. Entire sections of scientific papers are taken up with discussions of misspellings of gambeli and gambelli (Banks 2011). This goose breeds in the high arctic, in different areas, and tends to use different flyways (Wilson et al., 2018). Single birds show up in the winter, often migrating with large flocks of Canada Geese (and sometimes together with Snow or Cackling Geese). With exceptionally large flocks, it is not out of the question to also have Pink-footed Geese present, which is something to watch out for.
The consensus in the literature is that flavirostris is the species that shows up most often on the east coast of the US (Banks 2011) - there are no records of the European subspecies, A. c. albifrons, logged on eBird. To tell these two apart, note that flavirostris is generally darker on top, with a narrower white bar on the tail feathers, a thinner white hip-line on the flanks, and a flatter, longer orange bill (albifrons seems to have a stubbier bill, almost like a Cackling Goose) (Eli et al, 2020).
There have been several incidents of Greater White-fronted Geese (Western) - either gambelli or sponsa geese. Generally, these appear to not be single geese flying in with Canada Geese, but entire flocks that have erred far to the east, although there are some exceptions with single geese. The difference is most easily spotted by looking at the color of the bill; pink indicates gambelli/sponsa, while flavirostris are orange-billed as a rule.