Daisy Chaining ADC Sensors
'overkill' is a strange term for a cheaper solution! If you can find a cheap chainable A/D use it, but when 10 bits is sufficient I doubt you will find anything cheaper than a small microcontroller. 

I once designed something similar for a client, a grid of sensors. Each node was in a chain of IIRC 30 nodes, and each chain was 'hanging' from a master chain for 30 master nodes, for a total of ~ 1000 nodes. Each sensor node had a bootloader (I think the uC was an PIC16F88). All sensor nodes could be bootloaded in parallel. After startup each chain was enumerated (each node got a sequential number), so communication could target individual sensor nodes. 

The hardware of each sensor node was the uC, an HC TTL buffer chip, and an 7805 (otherwise the line would drop the voltage too much). Plus some decoupling caps and a few resistors. Four wires: gnd, power (=power down to reset/bootload), data in, data out (both daisy chained). The protocol was sufficiently timing-tolerant that the internal oscillator could be used under all voltages and temperatures.