Disklavier

My parents are moving into a new home after 44 years.   Dad insists 
that their 35 year old spinet piano (not a disklavier- I have that)
needs to be against an interior wall.   Cold and humidity from an 
exterior wall not good for piano.   They live in northwest part of 
Illinois.   Is this really an issue anymore with a home that is less 
than 15 years old and has good insulation?   Arranging their new 
living room would be so much easier if it is ok to put the piano 
against an exterior wall.

Thanks for anyone's help!

Bruce Conley