While Little House on the Prairie is regularly shown on reruns on television, it is not available for streaming on Netflix in the US. And it is not available in any country on Netflix either, so you cannot use a VPN to watch it.
Little House on the Prairie is available for purchase on DVD, in a deluxe remastered edition for the entire series that was released in 2018.
Little House on the Prairie has never been made available for streaming via Netflix, however it is available for streaming on Amazon Prime.