I'm not sure about the 180+10 situation, but I know for a fact you can book ADRs without a reservation number. You can provide them with a phone number and that will keep all the ressies connected. I did this in Oct 07 and Feb 07.
Poly: Mar90, Jul91, Mar95, Dec98, Jul00 (future DH 1st trip!)
WL: Oct02 (Honeymoon), Dec03, Feb07, Mar09 (DS 1st trip!)
Other trips: Apr94,96 offsite, Aug99 Dolphin, May07 DL
Dec09 AKV Kidani
Apr10 Poly (20th WDW "Anniversary")