Scott, be careful you sound like you're advocating the "it's OK because we do it in the US!" strategy. What I would ask you, and all other readers to consider is serviceability.
There is no reason why maintenance of the ILS cannot be carried out outside normal airfield opening hours, and as far as I'm aware (in the UK) no reason to notify the effect providing the equipment will be returned to use before next time the airfield is open (becasue using said kit is against regulations).
Secondly, many ILS installations require protection (i.e. ground movements adjacent to the ILS aerials are monitored & controlled when the equipment is in use)... when the airfield is closed there may be no need to control these movements, hence a serviceable ILS signal may be interfered with... and you'd be none the wiser in the cockpit :-(
Basically... a dodgy procedure I would strongly not recommend.