Here’s what I’ve finally used:
#!/usr/bin/env python3
import matplotlib
from matplotlib import pyplot as plt
from textwrap import wrap
data = range(5)
fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(data, data)
title = ax.set_title("\n".join(wrap("Some really really long long long title I really really need - and just can't - just can't - make it any - simply any - shorter - at all.", 60)))
fig.tight_layout()
title.set_y(1.05)
fig.subplots_adjust(top=0.8)
fig.savefig("1.png")