Should I give a heads up before enacting diplomatic clause?

I am on a two year lease and my diplomatic clause will be exercisable after 12 months on the 1 Feb 2020. I will comply fully with the clause conditions, provide proof of ceasing employment, pay out the remaining 2 months notice, reimburse pro-rated agency fee. But I unfortunately must leave Singapore mid-February. I need help deciding if I should tell them I will definitely be enacting my diplomatic clause, ie tell them NOW that I'll be giving notice on 1 Feb?

If I give notice on the 1 Feb that only gives me around 2 weeks to wrap things up before I leave. This may not be enough time to complete an inspection and handover (esp with Chinese NY) and thus guarantee that I will get back my deposit (is it guaranteed after inspection/handover?). If we fail to complete that in the time I will need to come back to Singapore. Not too difficult but I don't know what will happen with the apartment or the landlord when I'm out of the country. They might also not take kindly to me not sticking around for the full 2 months to comply with their inspections/handover, new tenant inspections, etc. Could I could lose my deposit?

But if I tell them now that gives them ample time before I leave the country and we can book in an inspection now. They also have the option to fill the apartment with a new tenant if I hand over the keys (as they will have an empty flat for half of Feb + March). But again there are also risks here, especially given how some landlords stick firmly to the contract. My landlord's agent has been difficult to deal with and they have both previously signalled negativity towards me leaving early. I also might not be allowed to give them a heads up that I am enacting the clause?

Also on another note my contract says I can enact the clause if I "cease to be employed by organisation" or transferred. I have not been fired, I have resigned and thus will technically cease to be employed by my employer. Is this enough to enact with my Resignation Acceptance Letter?