You don't have to wait for the DS1820s, you can do what I do, send the read request, go away and do other stuff and then come back around a second later to get the reading. I then send the next read request ready for the next time. Just a matter of learning to code without using delay.
I have one Arduino reading 4 DS1820s, polling the electric meter rotations,measuring AC waveform,watching the gas meter (Interrupt), turning the heating on and off and measuring light levels in 2 rooms.