The military use night vision equipment in some aircraft and the F111 from memory is equipped with terrain following radar. I don't think getting into the flat open plains of Avalon would cause them much grief. I think I could get into Avalon with 100ft cloud base and a Garmin 296.
Remember that Civilian rules don't apply to the military anyway, hence why you will see the Roulettes exit a loop over or towards the crowd when everyone else keeps more like 500 metres away.
When your equipment fails as Nick says, the DDTL approach is the most appropriate.