Many of us older timers get shorter due to loss of disc height in the spine. There are 25 of them in your spine. If you lose 1 mm in each one, you are down 1 inch total, which is what I have lost. Most of my loss space is cervical but you get the point.
If the bike is slightly large when older, this can be an advantage. Shorten and raise the stem will take weight off your neck and hands and because the upper body is a bit shorter anyway, it won't feel so bad.
Buy the bike.