Re: Tabata squats, single round or multiple?
Why not Tabata everything? Hit some push ups, sit ups, swings, squats, tuck-jumps, pull ups. There is plenty to do at home on a short budget. Do you have paralettes? Build a pull up bar. With a PU bar and a 'weight' (that could literally be anything heavy) you could be doing a sub'd version of the WOD most days. Body weight stuff abounds. There is that list posted around here.
Although the intervals with make you fit, eventually you will reach a point of dimished returns, however, if you're starting out, if you pay attention to form (not hurting yourself) and hit the intervals, you'll be rather fit in no time. Take your rest days...
Careful with tabata 'slow lifts' as you may be hurting yourself. Not certain you are, but take it easy. I think you'd see more benefit from a SS style for your DLs.