Sister may be better off here than as a lonely widow in Germany. So far, this is only hypothetical thinking.

Can you give some rough parameter which should be kept in mind. 

Apply for visa Now for the event.... which may happen in 2-5 years?

When is it too late to apply for a retirement visa?

Assuming nothing changes between now and then, a retirement extension is far and away the simplest and cheapest procedure for most people over 50. It's never too late to get one.

 

Pointless doing anything until nearer the time anyway.

15 minutes ago, THAIPHUKET said:

When is it too late to apply for a retirement visa?

There is no maximum age.

No need for the visa or extension of stay until the time comes.

Plenty of time to start planning for an O-A visa issued at home.

No need to bring cash to lodge in the bank etc. Keep the cash in Germany and get better interest rates etc.

O-A would give you two years of staying here with only one out/in at the the end of the first year.

All visas/extensions require out/ins or 90 day reports as a minimum.

Extensions of stay 90 day reports.

Multi entry visas ( except O-A ) out/ins every 90 days.

 

Long term solution, then forget this O-A VISA, go for UbonJoes suggestion.. extension oif stay based on retirement...

 

Suggestion II - If she can grab a thai-guy and support him and marry him, she can seek an extension of stay based on marriage to a thai national, without any demands for finance....

 

glegolo

17 minutes ago, glegolo said:

Long term solution, then forget this O-A VISA, go for UbonJoes suggestion.. extension oif stay based on retirement...

 

Suggestion II - If she can grab a thai-guy and support him and marry him, she can seek an extension of stay based on marriage to a thai national, without any demands for finance....

 

glegolo

Post of the year. ??????

On 7/21/2018 at 11:56 AM, THAIPHUKET said:

Apply for visa Now for the event.... which may happen in 2-5 years?

Not sure this is what you meant, but no, you cannot apply for a visa now which you plan to used 2-5 years from now.  AFAIK, the maximum validity period is one-year, meaning you must enter Thailand within one year after the visa is issued.

1 hour ago, wpcoe said:

Not sure this is what you meant, but no, you cannot apply for a visa now which you plan to used 2-5 years from now.  AFAIK, the maximum validity period is one-year, meaning you must enter Thailand within one year after the visa is issued.

Technically you must enter before the enter/use by date.

Depending on the visa type that may be 90 days or 365 days after the date of issue.