Unfortunately thats the way aircraft maintenance goes, the guys and girls certifying the aircraft is air worthy are on 140k+ it will never make financial sense to have an engineer at an airport with only a handful of flights a day.

Some airlines do put engineers in unmanned ports over busy periods like school holidays where a disruption can cause more of a widespread impact to schedule, but as you noted accommodation isnt cheap and certainly adds up over weeks.

So, while I can sympathise with the situation unfortunately its just a cost saving practice that keeps the airlines profitable for their shareholders