Well I don't have to guess, I have measured/calculated it, for an A0 truck at least
For a 1078 with the specified incandescent light sizes and everything turned on and high beam while standing on the brake pedal ~27A @13V
I measured the 24V load on my A0 truck and posted about it. Those numbers for 24V load are:
this 24V current was taken on the 24v lead to the cab using a 100A blue sea instrument shunt and gauge. I convert my 12v in the cab.
IGN on: 6A i had the 12v converter off at this point so that was trans and governor run solenoid.
Start and idle: still 6A which dropped to 3A(perhaps the air dryer heater engaged initially or something in the transmission load changed?)
all lights on, high beam(switched to LED and had no taillights for this test): +7.1)(10.1A total). I would expect a full light load of conventional bulbs to pull ~14A@24V
heater blower on high: +7.4A(17.5A total). The heater blower was the largest single 24v load...
wiper on high: +2.1A(19.6A total)
so total load was 19.6A@24v. when I have all my lights(tail and led habitat marker lights), I suspect it will be ~22-25A
@24v...
A standard incandescent lit 1078 truck will be ~26A with everything fed via 24v...
an A1 will probably be a little more current powering the ECU vis the run solenoid, but not much more, and LED lights will reduce the load.
110A would be great, but an even more common 75A@24V alt would also work well... It depends on what batteries you are running.
Hurricane/high water rescue? I would NOT put the converter outside. That Victron I referenced above is not very large and should fit very easily under the passenger dash. It is also dead easy to wire there like in my video. i used 3 pre-made heavy gauge cables from my local autoparts store to interface the my converter. 24V from PP to converter, ground from dash to converter and 12V from converter to PP where I disconnected the 12V battery cable.
if you had a failure in the converter you could simply reconnect 12V from the batteries to the power panel and that would get you thru the mission and home pulling 12 out of the middle of the 24v batt temporarily...