What I know is---
Power's Hill---2wd HC to Rattlesnake Mesa top, then a MODIFIED 4wd vehicle down to TH. HC and lo range with good tires.
If you hike from mesa top add about 2 miles or so to trip.
That part of Rattlesnake will have intermittant pools, it is 4 miles to Garden from top of Powers Hill at TH. The Garden will have some water at spring, longer this drought the less it will be.
Deer Creek is 2wd HC access. Water at mud springs is too early to be useful. Don't count on anything till you get to the Garden. May be water at Corral but you will have to climb up canyon to get it.
Grassy Ridge/trail will have no water. To get to it it is either Rattlesnake/Pipestem/ West Divide with poor trail conditions past Rhode Peak and you must carry ALL water.
Other access if from East Divide, either from Garden or from head of Rattlesnake and go past Holdout which has water but is iffy right now.
At top of divide over to Kielberg will be trail spur to Grassy Ridge, which parts of trail is faint but ok. No shade and will be warm in there. Water will have to be carried in there to from either the Garden, or maybe Kielberg tank if Holdout is dry.
Better know your terrain to get to Grassy Ridge from west side. It's a long way, tough hiking, and little water.