Center only the axis (not the spy) (pgfplots/tikz)

Question

Context

I have the following image being produced with the following code:

Image

Code

\documentclass{article}

\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}

\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\usetikzlibrary{spy}

\usepackage{siunitx}

\usepackage{float}
\usepackage{adjustbox}  % This is to scale the entire figure so it doesn't mess up the spy

\begin{document}
    \begin{enumerate}
        
        \item I'm talking about a figure. It's a great figure. Glorious, I might add\dots Here's the figure:
        \begin{figure}[H]
            \centering
            \begin{adjustbox}{width=0.65\textwidth}
                \begin{tikzpicture}[spy using outlines={circle, magnification=3, connect spies}]
                    \begin{axis}
                    [
                        xlabel={Temperature ($\unit{\celsius}$)},
                        ylabel={Consumption (litres per hour)},
                        grid,
                        xmin=0,
                        xmax=110,
                        ymin=0,
                        ymax=60,
                        axis lines=left,
                        legend style={at={(0.5,-0.3)}, anchor=north},
                        tick align=center
                    ]
                    
                    \addplot[black, dotted, ultra thick, domain=15:105, samples=100] {(770 / x)-1.325};
                    \addlegendentry{$f(x)=\frac{770}{x}-1.325$}
                    
                    \addplot[orange, dotted, ultra thick, domain=15:105, samples=100] {71.1 * exp((-0.0235)*x)};
                    \addlegendentry{$g(x)=71.1e^{-0.0235x}$}
                    
                    \coordinate (spypoint) at (axis cs:102.5,6);
                    \coordinate (magnifier) at (axis cs:150,30);
                    
                    \end{axis}
                    
                    \spy[gray, size=3cm] on (spypoint) in node[] at (magnifier);
                    
                \end{tikzpicture}
            \end{adjustbox}
        \end{figure}
        
        \hrule  % This is just to give perspective on how the figure is centered.
        
        See? I said it was glorious, didn't I?
        
    \end{enumerate}
\end{document}

Problem

What I really want is only for the graph (the axes) to be centered, but the spy to be uncentered (relative to the page).

Answer 1

Great figure!

If you add overlay to a TikZ scope, that scope bounding box (the physical space it occupies) is not considered when computing the graphic's size.

So writing

 \spy[gray, size=3cm,overlay] on (spypoint) in node[] at (magnifier);

Will give you

Notice that the "spilling out" of the graph from the border goes unnoticed because you asked to ignore it... so you have to take care not to have it going outside the page area.