向尊敬的曹老师请教!

1.No matter in very hot summer or in freezing cold winter, he never uses air conditioners

问题：no matter + wh-疑问词或no matter + 名词（实际上是省略了what和系词be)都是it is no matter的省略形式:那么no matter+介词短语也是it is no matter的省略形式吗？该如何分析呢？

2.If you think life is wonderful and expect it to stay that way , then you may have a good chance of living to a ripe old age, at least that is what the findings of a new study suggest.

问题：这个大句子怎么分析？  如果at  least是主句，那then 引导的句子该怎么分析呢？