Truth be told, "Freedom", as defined as:
n. The condition of being free of restraints.
n. Liberty of the person from slavery, detention, or oppression.
Would fit squarely under level 2 "Safety" needs in Maslow's hierarchy. Therefore "Live Free or Die" would essentially translate as "Level 2 Needs fulfilled, or Deny me my Level 1 needs".
Basically, hardcore libertarians feel that nothing should keep them from fulfilling their physiological needs, and the only thing that might would be government force. if Government force is stopping your family from eating (See: bread lines in Russia during CCCP), You're already unable to meet your safety needs, which will naturally lead to revolt/rebellion.