Increasing pie chart size with matplotlib, radius parameter appears to do nothing

Trying to make the pie larger. Looking at the docs, and other places, it says to set the radius. It seems no matter which value I put in the radius there's no increase. I'm posting the full code and the image it generates.

import matplotlib.pyplot as plt


def autopct_generator(limit):
    """Remove percent on small slices."""
    def inner_autopct(pct):
        return ('%.2f%%' % pct) if pct > limit else ''
    return inner_autopct

labels = 'Frogs', 'Hogs', 'Dogs', 'Logs', 'Test', 'Test2', 'Test3', \
    'Test4', 'Test5', 'Test6', 'Test7', 'Test8', 'Test9', 'Test10', \
    'Test11', 'Test12', 'Test13', 'Test14'
sizes = [15, 30, 45, 10, 10, 24, 13, 18, 28, 20, 13, 15, 5, 1, 18, 10,
         10, 10]
NUM_COLORS = len(sizes)

fig1, ax1 = plt.subplots(figsize=(6, 5))

# set color theme
# https://matplotlib.org/api/pyplot_summary.html#colors-in-matplotlib
theme = plt.get_cmap('bwr')
ax1.set_color_cycle([theme(
    1. * i / NUM_COLORS) for i in range(NUM_COLORS)])

box = ax1.get_position()
ax1.set_position([box.x0, box.y0, box.width * 1.3, box.height])

_, _, autotexts = ax1.pie(
    sizes, autopct=autopct_generator(7), startangle=90, radius=1.8 * 1000)
for autotext in autotexts:
    autotext.set_weight('bold')
ax1.axis('equal')
total = sum(sizes)
plt.legend(
    loc='upper left',
    labels=['%s, %1.1f%%' % (
        l, (float(s) / total) * 100) for l, s in zip(labels, sizes)],
    prop={'size': 12},
    bbox_to_anchor=(0.0, 1),
    bbox_transform=fig1.transFigure
)
# fig1.set_size_inches(18.5, 10.5)
fig1.savefig('chart.png')

If you turn on the axes of the pie chart,

ax.pie(..., radius=1800, frame=True)

you'll see that the radius is indeed applied correctly.

If you want to let the axes appear larger in the plot, you may use the subplot parameters.

fig.subplots_adjust(left,bottom,right,top)

Example code:

import matplotlib.pyplot as plt

sizes = [15, 30, 45, 10, 10, 24, 13, 18, 28, 20, 13, 15, 5, 1, 18, 10,
         10, 10]
labels = ["Frogs %s" % i for i in sizes]

fig1, ax1 = plt.subplots(figsize=(6, 5))
fig1.subplots_adjust(0.3,0,1,1)


theme = plt.get_cmap('bwr')
ax1.set_prop_cycle("color", [theme(1. * i / len(sizes)) for i in range(len(sizes))])

_, _ = ax1.pie(sizes, startangle=90)

ax1.axis('equal')

total = sum(sizes)
plt.legend(
    loc='upper left',
    labels=['%s, %1.1f%%' % (
        l, (float(s) / total) * 100) for l, s in zip(labels, sizes)],
    prop={'size': 11},
    bbox_to_anchor=(0.0, 1),
    bbox_transform=fig1.transFigure
)

plt.show()