Getting an ancestor property value can be done by binding to its element name. Here's an example

<Grid Width="{Binding Width}" Margin="{Binding Margin}">
	<Border BorderBrush=" #FF17447E" BorderThickness="5">
		<StackPanel Name="MainStackPanel" Orientation="Vertical">
			<ScrollViewer Height="{Binding ElementName=MainStackPanel, Path=ActualHeight}">
				<ItemsControl ItemsSource="{Binding Rows, FallbackValue=Rows}" Background="Transparent">
					<ItemsControl.ItemsPanel>
						<ItemsPanelTemplate>
							<StackPanel Orientation="Vertical"/>
						</ItemsPanelTemplate>
					</ItemsControl.ItemsPanel>
					<ItemsControl.ItemTemplate>
						<DataTemplate>
							<ContentPresenter Content="{Binding}" Height="30"/>
						</DataTemplate>
					</ItemsControl.ItemTemplate>
				</ItemsControl>
			</ScrollViewer>
		</StackPanel>
	</Border>
</Grid>

As always, feel free to comment, or ask