For amazon prime video it shows that "best" quality video content (1080p) consumes around 6.7 GB per hour.4. 1080p consumes 1.5 GB per hour, so 10 hours of streaming per day can be done comfortably. I highly doubt even combined viewing of a family would be 10 hours.
I am surprised you would prefer the less flexibility of daily FUP instead of monthly FUP where you can download/stream max on any day you prefer and not lose the FUP of other days.
But anyway to each his own.