expression
any number of people; as many people as one likes
Used to indicate that there is no limit on the number of people; often implies that many people are welcome or can be accommodated.
この会場は広いから、幾人でも入れるよ。
This venue is large, so any number of people can fit.
パーティーには幾人でも招待していいですよ。
You can invite as many people as you like to the party.