@dukes1963
With Orange you can have up to 3 phonenumbers.
If you do not charge the card, after a while the number get lost.
The time depends on the value of RDS you charge. Maximum is three month.
Solution: find a local person who take care and use the chip once in a while, or load the card. Important: It is not enough just loading the card! you mus tmake min. 1 call!
Example: my friend is away for 6 month per year. I buy every month for 100 RDS a phonecard and load the phone, make just one call. The miutes accumulate and when he is back he has plenty money for calls.
Maybe a business idea?

Sim-Card-sitter.