How to use an instrumentation amp?
You need to respect the amplifier input common mode range (and output range). If your amplifier (I'll assume it's an AD8221 inamp) had large power supply voltages your bridge configuration would be fine. You're putting about 0.7mA through the RTD element, which is reasonable for a Pt100. Your full-scale span will be 100mV, so you need sufficient gain in the inamp to give you full scale span for the ADC. If it's 2.5V, then G = 250. 

You might want to use a bit lower than 100 ohms if you want to cover 0 degrees C for sure. 

The problem is that the valid range of the AD8221 looks like this with +/-5V supplies: 



There may be other instrumentation amp types that can work acceptably with a single 5V supply (you would probably have to decrease the 100R resistor a bit to offset the minimum output above zero). Also note that it can't get to 5V output. 

Another option is to create a -5V supply using an ICL7660 or similar part.