Grammar meaning of でも in 何泊でもどうぞ

Question

……まあ。本当は素晴らしい剣なのですね。そんなものをお預かりできるのでしたら、何泊でもどうぞ

I know that でも can mean something like "Even", so 何泊でもどうぞ in this context probably means something like "Even if (でも) you stay as many nights as you want (何泊), it's fine/feel free to do it, but I'm not so sure, can someone explain the usage of でも here for me?

Answer 1

Your understanding is basically correct.

As a pattern, it is possible to think that 何/どの/どこ etc + ても/でも as no matter /...ever, which means roughly the number does not matter (in your case the number of nights). Literally your sentence means no matter how many nights you stay, please (stay).

Examples:

• 何度やってもうまくいかない No matter how many times I try, it does not work
• 何回聞いても忘れる No matter how many times I'm told, I forget it (easily).
• どんな手段を用いてもかまわない I don't care no matter what means you use.
• どれだけ寝てもまだ眠い However much I sleep, I still fell sleepy.
• どんな猫でもかわいい Whichever cat it is, it is cute.

As seen in the last example, it is not always natural to use no matter/...ever, it would be more natural to use as long as or simply any.