Allow TextBox to be resized but not to grow on user input

I have a TextBox defined inside a window like so:

<Window x:Class="NS.MainWindow"
    ...
    SizeToContent="WidthAndHeight">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="100" />
            <ColumnDefinition MinWidth="200" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition MinHeight="50" />
        </Grid.RowDefinitions>
        <TextBlock Grid.Column="0" Grid.Row="0">Description:</TextBlock>

        <TextBox Grid.Column="1" Grid.Row="0" TextWrapping="WrapWithOverflow" />
    </Grid>
</Window>

The problem is that when the user types in the TextBox it expands to the right since only the MinWidth is set. What I really want is the text to wrap to the next line. I can get it to do this if I change the MinWidth on the column to be Width instead. However if I do this, then the TextBox no longer resizes when the Window is resized.

Is there a way I can have both? (i.e. resize only on Window resize, otherwise wrap)