Why subplots are not taking all space allowed by figure in Matplotlib embedded with Tkinter?

I want to show a lot of subplots in a Tkinter window and be able to scrolldown to see all the plots with a good size. However, it is all packed and it seems that the subplots don't take all the space allowed in my figure and only restricts to the space of the window. How can I make it more spaced out and make the subplots bigger?

I've tried different paddings with the tight_layout() option, changing the figure size and other parameters of Tkinter like the fill or expand in my widgets.

import tkinter as tk
from tkinter import Scrollbar
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

import matplotlib.pyplot as plt

class ScrollableWindow:

    def __init__(self, master, fig, **options):

        master.geometry("%dx%d+0+0" % (800, 500))
        master.focus_set()

        fig_wrapper = tk.Frame(master, width=800, height=fig.get_figheight())
        fig_wrapper.pack(fill=tk.BOTH, expand=True)

        fig_canvas = FigureCanvasTkAgg(fig, master=fig_wrapper)

        scrollbar = Scrollbar(fig_wrapper, orient=tk.VERTICAL, command=fig_canvas.get_tk_widget().yview)
        scrollbar.pack(side=tk.RIGHT, fill=tk.Y)
        fig_canvas.get_tk_widget().pack(fill=tk.BOTH, side=tk.LEFT, expand=True)
        fig_canvas.get_tk_widget().config(yscrollcommand = scrollbar.set, scrollregion=fig_canvas.get_tk_widget().bbox("all"), width=800, height=1000)



n_col, n_row = 3, 11

fig, axes = plt.subplots(figsize=(n_col,n_row*2), ncols=n_col, nrows=n_row)
for i in range(axes.shape[0]):
    for j in range(axes.shape[1]):
        axes[i,j].set_xlabel("xlabel")
        axes[i,j].set_ylabel("ylabel")
fig.tight_layout()
showStatsWindow = tk.Tk()
showStatsWindow_ = ScrollableWindow(showStatsWindow, fig)
showStatsWindow.mainloop()

Here's an example with empty plots of what it looks like. I want to have 3 or 4 subplots per row, but it is all squeezed together. As you can see, I have more space down in my window and it changes with the figsize parameter but it's all blank.

from Why subplots are not taking all space allowed by figure in Matplotlib embedded with Tkinter?