title: How to position suptitle
body: <p>I'm trying to adjust a <code>suptitle</code> above a multi-panel figure and am having trouble figuring out how to adjust the <code>figsize</code> and subsequently position the suptitle.</p>
  
  <p>The problem is that calling <code>plt.suptitle("my title", y=...)</code> to adjust the position of the suptitle also adjusts the figure dimensions. A few questions:</p>
  
  <ol>
  <li><p>where does <code>suptitle(..., y=1.1)</code> actually put the title? As far as I can tell, the documentation for the <code>y</code> parameter of suptitle points to <a href="https://matplotlib.org/api/text_api.html#matplotlib.text.Text.set_y" rel="noreferrer">matplotlib.text.Text</a>, but I don't know what figure coordinates mean when you have multiple subplots.</p></li>
  <li><p>what is the effect on figure size when specifying <code>y</code> to <code>suptitle</code>?</p></li>
  <li><p>how do I manually adjust figure size and spacing (<code>subplots_adjust</code>?) to add a figure title per panel and a suptitle for the entire figure, maintaining the size of each ax in the figure?</p></li>
  </ol>
  
  <p>An example:</p>
  
  <pre><code>data = np.random.random(size=100)
  f, a = plt.subplots(2, 2, figsize=(10, 5))
  
  a[0,0].plot(data)
  a[0,0].set_title("this is a really long title\n"*2)
  a[0,1].plot(data)
  a[1,1].plot(data)
  
  plt.suptitle("a big long suptitle that runs into the title\n"*2, y=1.05);
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/y8c2v.png" rel="noreferrer"><img src="https://i.stack.imgur.com/y8c2v.png" alt="enter image description here"></a></p>
  
  <p>Obviously I can tweak y each time I make a figure, but I need a solution that generally works without manual intervention. I've tried both constrained layout and tight layout; neither works reliably with figures of any complexity.</p>