You can contact the Council who should be able to advise on the council tax. Ours were incredibly helpful.
Empty properties look empty after a while, so think about how you want them to remain secure.
Insurance, you will need to get specialist empty property insurance and there are clauses (like leaving loft access open in case of fire/smoke damage).
Utilities will need sorting. I suggest you keep the heating on, on thermostat, to save issues further down the line. Also consider electricity and some times switches/smart plugs you can control remotely.
And speak to a couple of letting agents to see if they will do a pop in/management service (or can recommend someone) for you.
If there is a garden, that is the biggest giveaway the property is empty so you will need to factor that in. We paid for a gardener once a quarter to stay on top of the worst of it. And a window cleaner twice in 12 months.
Also worth considering changing locks, unless you are very certain who has spare keys.
So very sad for you. Even harder when you are overseas - it is an added layer of administrative complications.