The way I see it, the English adverbial "at least" has two interpretations:
Used with numbers to express a minimum:
The temperature has to reach at least 98° before we'll turn on the air-conditioning.
At least three people have told me the same thing.
Used to express situations one is thankful for in contrast to the alternative; "you can be glad that..."; thank God:
At least your children aren't in jail. (=like mine are)
The elevator's broken, so we have to take the stairs. At least it's only four floors. (=and not twenty!)
Does Russian по крайней мере also cover the second usage, or just the first?
Anything else I should know about it?