Well, it helped that IIRC the SOP during wartime would have been for them to sit in the noisy Arctic ice until the order came to launch. Not the easiest of places to track boomers, and there would have probably have been an Akula or Victor III sitting nearby to spice things up.
Either that or they've have bastioned them and put them in the protection of a minefield, but I suspect they would have done that more with the Deltas.
