Nokogiri: parsing XML document missing enclosing parent entity

I want to process an XML document that lacks an overarching enclosing entity. (Yes, that's the file I'm given. No, I didn't create it.) For example:

<DeviceInfo>
  <Greeting>Crunchy bacon!</Greeting>
</DeviceInfo>
<InstantaneousDemand>
  <TimeStamp>0x1c722845</TimeStamp>
</InstantaneousDemand>
<InstantaneousDemand>
  <TimeStamp>0x1c72284a</TimeStamp>
</InstantaneousDemand>

When I parse the file using Nokogiri's XML method, it (predictably) only reads the first entity:

>> doc = Nokogiri::XML(File.open("x.xml"))
>> doc.children.count
=> 1
doc.text
=> "\n  Crunchy bacon!\n"

I could read the file as a string and wrap a fake enclosing entity around the whole thing, but that seems heavy handed. Is there a better way to get Nokogiri to read in all the entities?