Plotting pivot table results from two groups into subplots in Python

Question

I have created a pivot table with pd.pivot_table with two columns loc and sub resulting in the following table:

#example data
import pandas as pd
import matplotlib.pyplot as plt

df = pd.DataFrame({'times': ['2019', '2020', '2019', '2020', '2019', '2020', '2019', '2020'],
                   'values': [0, 5, 10, 15, 3, 5, 10, 15],
                   'sub': ['N', 'N', 'P', 'P', 'N', 'N', 'P', 'P'],
                   'loc': ['1', '2', '1', '2', '1', '2', '1', '2']})

Now I want to make subplots for all uniques of loc separately but with all the sub uniques in the same subplot. Using this code results in 2 columns for the sub uniques with the number of rows as loc uniques:

subs = ['N', 'P']
locs = ['1', '2']

pd.pivot_table(df.reset_index(),
               index='times', columns=['loc', 'sub'], values='values'
               ).plot(subplots=True, kind='area', grid=True, legend=True, stacked=False, sharex=True,
                      layout=(len(locs), len(subs)))

Example results

This is the current plot result with all instances separated into subplots:

The ultimate goal is to merge the different sub columns.