Remortgage without a mortgage

NOLU

Hi all.
First time poster, and need some advice.

We have been mortgage free for about 5 years.
Now that our 3 children have all grown up and flown the nest, we have decided that we'd like to buy a holiday home in Turkey and would like to raise the money (100k) to do this using our house.
I'm not sure where to start or how to go about getting the best interest rate.

My wife suggested that maybe we could down size and move to a more affordable area, in order to raise the money and so allowing us to become cash buyer's, but I don't think that she really wants to do that, and neither do I if in honest.

Ideally we would like to buy a place in the sun primarily as a rental but would also use it ourselves for about 6/8 weeks of the year.