Hoi Johan,
This may be doable with some "css magic", although i would expect some resize/repaint problems here. Another option would be to link to a different page, where the map is shown in fullscreen. This will also depend on how your template is built, so i can't give any general advice here.
if you look here:
developers.google.com/maps/terms
you will find the current Terms of Use, and to be honest: i don't understand them 
- "i'm not a lawyer".
What's also irritating is that they change these Terms every now and then (currently it says "Last Updated: November 13, 2014"). So it's possible that they have dropped or changed the amount of requests limitation in the meantime.
Therefore i encourage users to use the OpenStreetMap layers - no problems there!
If you do want to use the Google layers, the best thing you can do imo is to get in contact with Google directly, describe what you want to do with your site and maps, and get a "Go or No-Go" from them directly. Everything else would be guess work...
cheers, Frank