The answer to that question is very subjective. Your best bet is to create an XPE (Xilinx Power Estimator) to enter your design criteria to get an accurate number. The worst case 7030 estimation is in the 7.5W range, however with the smaller 7010 device and a nominal design the estimation is only 2.5W. I hate to give a non-precise answer, but honestly it will vary somewhere between those figures based on your device selection and your load profile. For the thermal resistance, check out Xilinx UG865, page 97 has info for the different device packages - https://www.xilinx.com/support/documentation/user_guides/ug865-Zynq-7000-Pkg-Pinout.pdf
