sns.boxplot(data=df, width=0.5)
plt.title(f'Distribution of scores for initial and resubmission\
\nonly among students who resubmitted at all.\
\n(n = {df.shape[0]})')
I want to use a bigger font, and leave more space in the top white margin so that the title doesn't get crammed in. Surprisingly, I am totally unable to find the option despite some serious googling!
The basic problem you have is that the multi-line title is too tall, and is rendered "off the page".
A few options for you:
the least effort solution is probably to use tight_layout(). plt.tight_layout() manipulates the subplot locations and spacing so that labels, ticks and titles fit more nicely.
if this isn't enough, also look at plt.subplots_adjust() which gives you control over how much whitespace is used around one or more subfigures; you can modify just one aspect at at time, and all the other settings are left alone. In your case, you could use plt.subplots_adjust(top=0.8).
If you are generating a final figure for publication or similar, you might be aiming to tweak a lot to perfect it. In this case, you can precisely control the (sub)plot locations, using add_axes (see this example https://stackoverflow.com/a/17479417).
Here is an example, with a 6-line title for emphasis. The left panel shows the default - with half the title clipped off. The right panel has all measurements the same except the top; the middle has automatically removed whitespace on all sides.
import seaborn as sns
import numpy as np
import matplotlib.pyplot as plt
data = 55 + 5* np.random.randn(1000,) # some data
vlongtitle = "\n".join(["long title"]*6) # a 6-line title
# using tight_layout, all the margins are reduced
plt.figure()
sns.boxplot(data, width=0.5)
plt.title(vlongtitle)
plt.tight_layout()
# 2nd option, just edit one aspect.
plt.figure()
sns.boxplot(data, width=0.5)
plt.title(vlongtitle)
plt.subplots_adjust(top=0.72)
