yeah.. I ended up looking it up...
So the higher end channels for 802.11n in the US, 149-165, correspond with 5.745Ghz-5.825Ghz.
5.8Ghz cordless phones use 5.725-5.850Ghz. So yeah.. there is overlap there. So far 149 seems to be OK with my wifi.
I may end up changing to a DECT 6.0 phone. BTW.. DECT 6.0 is 1.920-1.930Ghz here in the US. or find some older 900Mhz phone