You can also set figure size by passing dictionary to rc parameter with key 'figure.figsize' in seaborn set method:

import seaborn as sns

sns.set(rc={'figure.figsize':(11.7,8.27)})

Other alternative may be to use figure.figsize of rcParams to set figure size as below:

from matplotlib import rcParams

# figure size in inches
rcParams['figure.figsize'] =