The only way I've found to achieve this is by creating an HTML file that creates a huge iframe and loads your Google Maps page inside it:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<iframe width="4000" height="4000" frameborder="0" scrolling="no"
marginheight="0" marginwidth="0" src="http://maps.google.com/maps">
</iframe>
</body>
</html>
Replace http://maps.google.com/maps in the code above with the URL generated in Google Maps when you click the link icon, and then inside Paste HTML to embed in website. Don't copy the entire <iframe ... code, just the src of the generated iframe tag.
This will create a 4000px by 4000px map. Change the width and height parameters above if that's not big enough (or too big). If your browser tries to paginate the map rather than resize it down to one page, try using a screen-capture browser extension to save a screengrab of the entire 4000x4000 page as an image, then print the image file.
A caveat, though: printing a 4000x4000 map on letter paper will produce street names that are far too small to read. In general Google's labels are sized appropriately for the zoom size, which more or less correlates with printing at that size/zoom. To print a larger (in width/height, not zoom level) map and still be able to read the labels, you'll need to print on large paper like a poster.
Best Answer
I don't believe so. I thought you might be able to by changing your mouse wheel's zoom in your operating system (Windows: Control Panel > Mouse > Wheel). However, I just tried it and it doesn't do anything either.
It seems that even in embedded maps, the API only allows an enable/disable. It doesn't have any settings related to it.