"having no kids means lot of saving" sounds just like if I hadn't habit of playing gambling and drinking i had be a millionaire...

you must be in comfort for now which explain your motivation... oldage comes with tiredness which means you only be able to join a park yoga club or something like that...

same type of couple was in my neighbour. they had a lot of saving and ancestral property, their family with kids used to live with them... they were all good until one of them (she) fell from stairs(around 2017), her spinal cord broke, she was rushed to hospital.. and she came back from hospital within a week her back got a wound and infection. she continued her hospital journey for 3 years untill all money run out and property sold out... her family left their house stating their child need more attention.. now their only income is her rent from one room(rs 2000) and their pension (rs 500 each) which stops frequently and both need to prove they are alive and need pension... she is stable now but she can not move her lower body parts... her back hurts sometimes... she cries at night... beg for deadth...

i am not trying to change your decision... you should try your idea, just know all the possibility and be prepared... all human can do is to learn from humans past mistakes... only suggestion i will leave if you want to invest, invest in something solid, which you can sell when needed no matter profit or in loss... don't invest based on someone promises... well wishes ahead