Condensation on the windows?

we endeavour to keep condensation in our home to a minimum because we suffer so badly with it .....we are a large family living in quite a small house so obviously dampness in the winter months is a big issue! Apart from opening windows during the day and running a dehumidifer during the night there isnt much else we can do .The problem is, if we were to leave the house empty for a week or so, I am sure, as a neighbour found out recently , that upon return the house and windows will be damp ridden ....my question is .is there a substance you can leave arround the house such as salt or other chrystals to collect the moisture for me