Translation of outline in Spanish

I hope you can understand the corrections this way... Two small errors. let me know if there is a word or sentence or phrase that you didn't understand! I will try to think more on the "since" question...
Hi! Thank you for your invitation and for your very kind messages. I'm sorry but it is very late here and I prefer to write you tomorrow. When is the best time to chat? See you later than.
It was a two hour flight above the vast area of Patagonia. On the left side of the flight path there were mostly arid areas, some covered in snow. On the right side of the airplane were the mountains.