Managed to get Sleep Mode enabled on the remote transmitter after using great instructions from a Digi Knowledge Base Article - a Cyclic Sleep Mode Example that was intended for the XStream/XTend models, but it appears that Sleep Mode parameters are the same for both firmwares. Hoping this will extend the remote's 9V battery life.
After taking the dogs out for a walk on Nose Hill and braving the chilly winds to get to the top, I connected the battery to the Xbee, closed the lid, and placed the box at the base (about 1 foot from ground height) of a bush.
Covered it with a prickly thorn bush - but if you look close you can still see the small white wire antenna extending about 2" upward. Although low to the ground, the box is still very much elevated above the transmitter, with no real obstructions below.
From the vantage point above the bush you could see the 64th Ave intersection and a piece of the parking lot where I intended to do my testing later that day. There's plenty of trees in the line of sight and the receiver location at the base of the bush is not ideal, but I needed to keep fairly hidden from local hikers.
Interior of truck shows sophisticated setup?
Frigging cold to be out playing with radios
Transmitter Antennna (5" in center - not light standard at left) extended out from truck roof to sit on slightly open sunroof.
View from the Parking Lot - receiver located in bush below the left most tree in isolated stand of three in center of view at top of hill.
Google Earth View of the receiver and transmitter locations - click on image to get a better view - or if you want to look at receiver location for yourself, coordinates are: N 51 degs 06.610 minutes and W 114 degs 05.736 minutes. Using the Google Earth ruler tool, the distance came out to be 820m. Not sure if that's horizontal or line-of-sight?
After starting up the X-CTU range test, I had to wait the obligatory 16 retries before the Sleep Mode Cycle picked up on the fact it was being sent some data. I considered it a great success when it returned 196 packets as Good and 41 Bad - 80% success!
TEST #2: Front of Parking lot - facing sign. Trees slightly visible in distance. 60% success
TEST #3: Front of Parking Lot - Facing hill directly in front of truck. 10% success.
TEST #4: Alley across street. 1.0km distance. Good view uphill. 90% success.
TEST #5: Alley - further down road. No visibility. 10% success.