How can I see the plan for ONE statement in a stored procedure?
I don't think there's a way to do that in SSMS.

You should use Sentry One Plan Explorer for this.  It's a free tool that provides an alternative way of viewing SQL Server execution plans.

I've run this code on my local copy of the Stack Overflow 2010 sample database:

CREATE PROCEDURE #sp_TestQuery
AS
SELECT COUNT_BIG(*) FROM dbo.Users u WHERE u.Id &gt; 10;
SELECT MAX(p.CommentCount) FROM dbo.Posts p WHERE p.Id &gt; 1000;
SELECT MIN(v.BountyAmount) FROM dbo.Votes v WHERE v.Id &gt; 100000;
GO

EXEC #sp_TestQuery;


Running the EXEC... line produces the problem you mentioned in SSMS:



One option I have here is to at least resize the different panes, by dragging the border between them.  If I wanted to mostly see the middle query:



But that's still not ideal.  The default view in Plan Explorer shows me a list of statements at the top, and I can click on each statement to view the graphical plan below it.  Here's the middle query in Plan Explorer: