What if you were to instead plan on sleeping for 8 to 9 hours? Sleeping only 6 to 7 hours is suboptimal for most people. Spending 9 hours in bed and getting 8 hours total sleep would probably be a good target (for most people). I imagine the 3-4 hours of disrupted sleep would become more efficient and shorter if you didn't wake up in the middle from alarms and etc.

Also, as usual, don't listen to random folks on the internet.