You sure can!

Python classes:

• class MyBaseForm
• class MyInheritedForm(MyBaseForm)
• class MyInheritedFormTwo(MyBaseForm)

Directory structure

• my_base_form
  ---- extension.py
  ---- templates
  -------- index.html
• my_inherited_form
  ---- extension.py
  ---- templates
• my_inherited_form_two
  ---- extension.py
  ---- templates
  -------- index.html

Let's say we called:

self.get_template('index.html', {})

From:

MyBaseForm: returns my_base_form/templates/index.html
MyInheritedForm: returns my_base_form/templates/index.html (inherited)
MyInheritedFormTwo: returns my_inherited_form_two/templates/index.html (overridden)