The house is big enough to jog in. Long corridor, empty family room, easy to circuit, down and around and back, tag the bannister to complete a lap, barefoot on carpet, low impact. Repeat a few dozen times, you'll rack up the miles.
Finish with wind sprints, down the hallway and return, tag the bannister, hauling ass, surprised and elated and endorphined.
Making do with what you have.