Ryouichi7

Certainly high risk, let us know how it goes.

Do you have any adult children who are living in the US and are USC21) ? If you do,  one of them can petition for you under IR 5 .  Sibling petitions take many years  Parent petitioned 12 to 15 months. 

SB1 seems a very long shot, OP has GC and can not be refused entry, could end up in front of an IJ but if that happened likely to be years away and can argue her case then.

Absences of over 12 months are considered abandonment of resident status in the US. Without a previously approved reentry permit .. valid for 2 years only and must have been applied for before leaving the US .. or being able to show that the length of your stay was outside your control.and being granted an SB1.. returning resident visa . very big challenge ... then it is pretty certain that you would not be considered to still be an LPR and may be refused entry or sent to immigration court if you were allowed to renter 
To get back to living in the US, you would need to be  eligible for a new immediate relative visa or if you landed a job where the
company was prepared to sponsor an employment based visa 

Did you get the reentry permit before leaving US? If not you might need to apply for Returning Resident visa at the US embassy.

You can contact USCIS directly, the phone number is on the website.