원하시는 것이 어떤 것인지 헷갈리네요.

각주에도 더블스페이싱을 유지하고 싶다는 것인지, 유지하고 싶지 않다는 것인지?

setspace의 기능은 앞서 말씀드렸듯이 "본문" 줄간격을 싱글스페이싱, 1.5배 스페이싱, 더블스페이싱으로 변경하더라도, 각주와 플로팅의 줄간격은 싱글스페이싱을 유지하도록 하는 것입니다. 

 

\documentclass{article}

\usepackage{lipsum}

\usepackage[doublespacing]{setspace}
\usepackage{hyperref}
\usepackage[margin=1in]{geometry}

\title{No Title\thanks{This is just a dummy sentence. This is just a dummy sentence.}}
\author{No Name\thanks{This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence.]}}
\date{No Date}

\begin{document}

\maketitle

\begin{abstract}
    This is just a dummy sentence.\footnote{This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence. This is just a dummy sentence.}
\end{abstract}

\lipsum

\clearpage

\end{document}