Change chapter title size in Dissertate (or prevent long chapter title pagebreak)

Question

When using the Dissertate template/class for a dissertation, longer chapter titles cause formatting issues (chapter titles get moved onto the page after the chapter number, which looks awful.)

How does one either reduce the chapter title font, or prevent longer titles from bumping onto the next page?

Any help would be much appreciated (I don't see the font settings for \chapter{...} anywhere)

Here's the template https://www.overleaf.com/latex/templates/phd-thesis-and-dissertation-latex-templates-for-harvard-princeton-and-new-york-university-nyu/wkzvtymyxqvv

The Dissertate.cls is copied below (under the screenshots).

% -------------------------------------------------------------------
%  @LaTeX-class-file{
%     filename        = "Dissertate.cls",
%     version         = "1.0",
%     date            = "24 January 2014",
%     codetable       = "ISO/ASCII",
%     keywords        = "LaTeX, Dissertate",
%     supported       = "send email to suchow@post.harvard.edu",
%     docstring       = "Class for a dissertation."
% --------------------------------------------------------------------
\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{Dissertate}[2014/01/24 v1.0 Dissertate Class]
\LoadClass[12pt, oneside, letterpaper]{book}
% some definitions
\def\degreeyear#1{\gdef@degreeyear{#1}}
\def\degreemonth#1{\gdef@degreemonth{#1}}
\def\degree#1{\gdef@degree{#1}}
\def\advisor#1{\gdef@advisor{#1}}
\def\department#1{\gdef@department{#1}}
\def\field#1{\gdef@field{#1}}
\def\university#1{\gdef@university{#1}}
\def\universitycity#1{\gdef@universitycity{#1}}
\def\universitystate#1{\gdef@universitystate{#1}}
\def\programname#1{\gdef@programname{#1}}
\def\pdOneName#1{\gdef@pdOneName{#1}}
\def\pdOneSchool#1{\gdef@pdOneSchool{#1}}
\def\pdOneYear#1{\gdef@pdOneYear{#1}}
\def\pdTwoName#1{\gdef@pdTwoName{#1}}
\def\pdTwoSchool#1{\gdef@pdTwoSchool{#1}}
\def\pdTwoYear#1{\gdef@pdTwoYear{#1}}
\RequirePackage{color}
\usepackage{hyperref}
\RequirePackage[tiny, md, sc]{titlesec}
\setlength{\headheight}{15pt}
\pagestyle{plain}
\RequirePackage{titling}
\RequirePackage[palatino]{quotchap}
\RequirePackage{kvoptions}
\DeclareStringOption{School}[]
\ProcessKeyvalOptions*
\RequirePackage{packages/\Dissertate@School/style}
\RequirePackage{graphicx}
\RequirePackage{amssymb}
\RequirePackage{lettrine}
\RequirePackage[super,comma,numbers]{natbib}
\renewcommand{\bibnumfmt}[1]{[#1]}
\RequirePackage[width=5.75in, letterpaper]{geometry}
\RequirePackage{fancyhdr}
\usepackage[titletoc]{appendix}
\renewcommand{\setthesection}{\arabic{chapter}.A\arabic{section}}
\RequirePackage{setspace}
\RequirePackage{booktabs}
\RequirePackage[tight,nice]{units}
\RequirePackage{verbatim}
\setcounter{tocdepth}{1}
\RequirePackage{url}
\usepackage[titles]{tocloft}
\renewcommand{\cftsecleader}{\cftdotfill{\cftdotsep}}
\renewcommand{\cftchapfont}{\normalsize \scshape}
% \usepackage{fixltx2e}
\usepackage{ragged2e}
\renewcommand\bibname{References}
\renewcommand\listfigurename{Listing of figures}
\RaggedRight
\parindent 12pt
\RequirePackage{mathspec}
\setmathsfont(Digits,Latin,Greek)[Numbers={Proportional},SizeFeatures={{Size=-8, OpticalSize=8},{Size= 8-, OpticalSize=12}},]{EB Garamond}
\setmathrm{EB Garamond}
\widowpenalty=300
\clubpenalty=300
\defaultfontfeatures{Mapping=tex-text}
\newfontfamily{\smallcaps}[RawFeature={+c2sc,+scmp}]{EB Garamond}
\setromanfont[Numbers=OldStyle, Ligatures={Common, TeX}, Scale=1.0]{EB Garamond}
\setsansfont[Scale=MatchLowercase, BoldFont={Lato Bold}]{Lato Regular}
\setmonofont[Scale=MatchLowercase]{Noto Mono} % Font substitution for Source Code Pro
\RequirePackage[labelfont={bf,sf,footnotesize,singlespacing},
                                textfont={sf,footnotesize,singlespacing},
                                justification={justified,RaggedRight},
                                singlelinecheck=false,
                                margin=0pt,
                                figurewithin=chapter,
                                tablewithin=chapter]{caption}
\renewcommand{\thefootnote}{\fnsymbol{footnote}}
%\onehalfspacing
%\doublespacing
% an environment for paragraph-style section
\providecommand\newthought[1]{%
   \addvspace{1.0\baselineskip plus 0.5ex minus 0.2ex}%
   \noindent\textsc{#1}%
}
% Align reference numbers so that they do not cause an indent
\newlength\mybibindent
\setlength\mybibindent{0pt}
\makeatletter
\renewenvironment{thebibliography}[1]
    {\chapter*{\bibname}%
     @mkboth{\MakeUppercase\bibname}{\MakeUppercase\bibname}%
     \list{@biblabel{@arabic\c@enumiv}}
          {\settowidth\labelwidth{@biblabel{999}}
           \leftmargin\labelwidth
            \advance\leftmargin\dimexpr\labelsep+\mybibindent\relax\itemindent-\mybibindent
           @openbib@code
           \usecounter{enumiv}
           \let\p@enumiv@empty
           \renewcommand\theenumiv{@arabic\c@enumiv}}
     \sloppy
     \clubpenalty4000
     @clubpenalty \clubpenalty
     \widowpenalty4000%
     \sfcode\.\@m} {\def\@noitemerr {\@latex@warning{Emptythebibliography' environment}}
     \endlist}
\makeatother

Answer 1

It's the quotchap package that's setting chapter number/title font and placement. The following examples (after quotchap in the .cls) will adjust the font and placement of the chapter titles:

%move chapter number and title up towards top of page
\renewcommand*{\chapterheadstartvskip}{\vspace*{-4.0\baselineskip}}
%increase space between chapter title and chapter text 
\renewcommand*{\chapterheadendvskip}{\vspace{5.3\baselineskip}}
% Default: 100/130 so this setting shrinks the chapter number and title font 
\renewcommand*{\chapnumfont}{% \usefont{T1}{@defaultcnfont}{b}{n}\fontsize{80}{110}\selectfont