If you don't find the opportunity you are looking for, you might like to have a look at TrustedHousesitters.com
We've started using this platform and that consists to match people who need to leave for a short period, so they need someone to take care of their house, animals and/or garden while they are away, to people who love animals and want to travel or just spend a weekend off. By offering our time and care for other's pets, we can enjoy staying for free in locations world-wide, whether we are looking for a weekend or a few months of stay.
In case you consider to join to this community, follow the link above and get 25% off membership!