Widgets are flexible enough to be able to add them to any template, be that a normal template or to individual page nodes.
To add a widget to a sidebar on a page node, for example the Members Online Now widget, you can include the following code, anywhere in your page node template:
<xf:widget class="XF:MembersOnline" opt-limit="50" opt-staffOnline="1" title="Online Members" position="sidebar" />
As you can see, you can use any widget you like, and configure it directly in the template. Alternatively, if you already have a widget configured on another page such as the
forum_list_new_posts widget from the forum list then you can just call that as follows and it will automatically use the same configuration:
<xf:widget key="forum_overview_new_posts" position="sidebar" />