Going to US with likely GC abandonment - need visa?

[amplexity]

Hi,
I've had a permanent GC for 10 years, but returned home to attend to my aging parents 1.5 years ago. I returned to the US frequently, because my daughter, my house and my business are still there. The last time, I was told that if I leave again, I will have to surrender my GC, because I'm not allowed to 'live' away from the US. I'm willing to surrender the GC as I have to stay in Germany for a good while longer, maybe entirely. However, I'm still going to visit my daughter and attend to business frequently.
Since I still have a GC - should I apply for a visa or visa waiver (ESTA) before travelling this week? Or would that be interpreted as a negative action? I would obviously like to keep the GC as long as I can... but right now, I just don't want to be refused entry and I really want to avoid being grilled by nasty immigration officers.
Did anyone here have a similar situation? What happened? Any other advice??
Thanks all!

[inadmissible]

When were you last in the United States, and for how long?

I'm not convinced you have abandoned your permanent residence, at least not yet

It seems to me that your home is in the United States and you have been abroad temporarily

[abumiqdad]

is there a reason why you did not apply for re-entry permit before leaving?

[amplexity]

sadly, I have to admit that the sole reason for not applying to 'reentry' is ignorance. I simply didn't know it was available.

is there a reason why you did not apply for re-entry permit before leaving?

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I was in the US last time in March and April of this year. I'm traveling back to the US this week. So it hasn't been 6 months between these two stays. However, I first went back to Germany (for longer periods) in Jan 2016... by the time I realized I needed to apply for re-entry, it was too late (cause I was told that I need to be in the US when I get the interview, and since that could be anywhere from 6weeks to 4 months, and I could not fly over at the drop of a hat, I would not have been able to make the interview date).

When were you last in the United States, and for how long?

I'm not convinced you have abandoned your permanent residence, at least not yet

It seems to me that your home is in the United States and you have been abroad temporarily