Hoarding isn't deferred consumption; it's holding present goods in present form. The hoard is liquidity now, a present good. Time preference is expressed through exchange of present goods for future goods. Holding cash makes no such exchange; you keep present goods as present goods.

Crusoe saving fish to build a net isn't hoarding in the monetary sense. He's investing in a longer production process, exchanging present goods (fish, labor time) for future goods (net, greater fish yield). That's textbook low time preference. If Crusoe just piled up fish and never built anything, he'd eventually eat them. The pile isn't deferred consumption; it's inventory awaiting consumption.

In a monetary economy, if everyone holds cash and no one lends, the supply of loanable funds is zero. Zero supply at any positive demand means the market-clearing price (interest rate) approaches infinity. This doesn't describe Crusoe; he's not in a loan market. It describes a monetary economy where no one participates in the time market.