Automatic feeding for brine eating fish

[Johnny Reefer]

IMO if you feed it substantially over the days prior to your departure, it should be alright going without over the 8 days.
When I got back into aquariums back in '94 I left for 28 days running a cheapo POS Penn Plax auto-feeder. When I got back I had discovered that the thing had jammed on day one. Thus, my juvie Oscars went 28 days without a speck of food and they survived, albeit hungry.
I know with FW fish there is a "dry season" when food is scarce due to low water levels. Consequently, FW fish are "programmed" to deal with it. Not sure if/how this applies to SW, however.

HTH and cheers,