Target FIRE for Italy

40M childfree, single, and intending to stay that way. I work in the USA, but I am an Italian citizen. My long term plan is to semi-retire in Italy, but the timeline is unclear and depends on the target FIRE amount.

Current net worth is ~$1.9M in post-tax investment accounts (ETF, mutual funds and stocks), plus ~$120k in 401k.

As a GC holder, I might be subject to the exit tax when I leave the US. In Italy, I would like to rent first, ideally in a location in the Alps (Trentino, Valle d'Aosta, Veneto). I would like to keep up with my hobbies and current lifestyle: fine dining, traveling abroad, flying recreationally (gliders, GA airplanes), so not really frugal.

What is a solid amount for this plan, considering it will be no earlier than in 10 years, after I turn 50.