Consistent placement for page number with changing margins

Question

I have a document (letter paper) with a cover letter, some single column pages and some two-column pages. For readability I would like to use 1.5" margins for the single column pages and 1" margins for the two-column pages. I've done this using the geometry package and \newgeometry. However, when I compile the document the pages numbers (centered) move up and down, higher with larger margins and lower with smaller margins.

Here is a MWE:

\documentclass[10pt, letterpaper]{article} 
\usepackage{geometry} 
\geometry{letterpaper, margin=1.5in, marginparsep=7pt, marginparwidth=.6in}
\usepackage{multicol}

\begin{document}
hi

\newgeometry{margin=1in}  
\newpage
\begin{multicols}{2}
hello
\end{multicols}

\end{document}

I was wondering how I can keep the page number in a consistent position? but, I was also wondering what I should do, should I avoid these changing margins altogether? Should I leave it with the page numbers different on different pages?

I've tried:

\usepackage{fancyhdr}
\fancyhf{} % clear all header and footers
\renewcommand{\headrulewidth}{0pt} % remove the header rule
\cfoot{\thepage}
\pagestyle{fancy}

and calling \fancyhfoffset[E,O]{0pt} after each \newgeometry call but I figure something else must be needed to have the page number not move.

Answer 1

You can specify the footskip parameter

\documentclass[10pt, letterpaper]{article} 
\usepackage{geometry} 
\geometry{letterpaper, footskip=1in, margin=1.5in, marginparsep=7pt, marginparwidth=.6in}
\usepackage{multicol}

\begin{document}
hi

\newgeometry{footskip=0.5in, margin=1in}
\newpage
\begin{multicols}{2}
hello
\end{multicols}

\end{document}