Port expander (MCP23017) and software SPI / I2C

You could do very slow software SPI pretty easily over a port expander, and could even write your own SPI class which you could feed into existing modules.

I have literally just made digitalWrite/Read able to use an object passed in, so assuming you're using a 'cutting edge' build of Espruino (or 1v95 when it's available), you should be able to do:

var spi = {
  write : function() { SPI write code }
};
var cspin = {
  write : function(v) { write value to pin }
};
var disp = require("MAX7219").connect(spi,cspin);