I wouldn’t assume USNWR’s small weight on test scores dictates the relative weight of test scores and GPA in admissions. Some highly selective colleges that are clearly concerned about USNWR choose to be test optional, such as Chicago. Some have theorized that Chicago’s concern over USNWR rankings is one of the key reasons why they chose to be test optional. Various other highly selective colleges appear to be less influenced by USNWR and openly criticize them.
Regarding the OP’s question, it depends on both where you are applying and context. GPA is particularly sensitive to context. For example, a 3.7 while taking rigorous classes at HS known for harsh grading with only B grades in freshman/sophomore year classes not especially relevant to major… is not the same as a 3.7 while taking no honors/AP/IB classes in public HS with extreme grade inflation with straight B’s in junior/senior year classes relevant to major. I’d suggest looking at Naviance or similar for your HS, which may provide a better context.
The particular college and program within the college is also important. Among test required colleges, some highly selective colleges appear to favor having top scores more than others. In general colleges that have SAT/ACT scores above what you’d expect based on selectivity and hooks tend to favor high scoring applicants more than you’d expect. For example, a list of 75th percentile scores is below by college. WUSTL and Vanderbilt seems to have higher scores than one would expect based on selectivity, and scattegrams, suggesting a decent chance of admission for students with high SAT/relatively low GPA.
WUSTL – 35, 770/800
Stanford/Yale/Princeton – 35, 770/800
Vanderbilt – 35, 760/800
Columbia – 35, 760/800
Brown/Penn – 35, 760/790