Several storms later...

This is your basic "embedded mailbox". My snow-blower guy has sculpted out a niche to allow - barely - access to the mailbox, but it's getting to the point where the mail carrier may not be able to reach it from the truck. If we get another heavy snow I might need to make use of this clever life-hack suggestion:

 

makeitlabs.com/winter-mailbox-lifehack/

 

Done