I gave some thought to how I might recreate a bootstrap load using the MOSFETs and other components I have on hand. The problem I wrestled with was how to best recreate a MOSFET that looked like a resistor when turned on and not a dead short. Finally I tried a couple of combinations of the BSS83 MOSFET in series with a resistor or two. Finally I settled on a pair of resistors, one between Vdd and the FET's drain and the other between the FET's source and the rest of the circuit.