complex search within VS2015

I'm trying to run a search against a solution with 4 projects and thousands of files.

I'd like to return all aspx files that have <asp:gridview that do NOT have a width in place

Since the code is often on multiple lines its getting the best of me.

example:

<asp:gridview id="oneblock" width="100% runat="server" SelectMethod="GetReasonCodes">

and

<asp:gridview id="oneblock" width="100% 

runat="server" SelectMethod="GetReasonCodes">

are OK, but 

<asp:gridview id="oneblock" 

runat="server" SelectMethod="GetReasonCodes">

is NOT, thats the one I'd like to find. Does that make sense?