Just remember there is a "longer than reset times" maintenance planned for tomorrow, and when 6.1 hits the power-leveling days in the garrison may be over for good. So focus on getting all your little guys up today since you can XP up even the level 1's. That way if 6.1 does hit tomorrow you got the most bang for your minutes (and treats). If 6.1 doesn't hit then you can continue on with the planned leveling as per normal.
Which means we might not get a Jahan day so that could be it with tonight's report.
Most of my pets that are super low level aren't really great pets to start or I just purchased them that day. If the pet is that great I'll get them up to at least 12-15 so they are ready for super-pet-leveling days like today. My top on that list is Xu-Fu (he's 17) and my replacement Menagie Custodian (new one is now 15. I helped out a friend new to collecting so she could do Garga, she already had a level 25 Starlette and needed a 2nd strong mech pet so I gave her my 25 for her level 1).
I only use those XP bonus treats at the Garrison Dailies. I feel like when I use them out in the wild I waste time with traveling from pet to pet. So right now I have 3 treats from my last run at the Pandaria fable quests and I have 32 Pet charms. That should help me get a slew of targetted pets leveled up tonight.
If 6.1 ruins things tomorrow the it is what it is. An long time pet collector told me how he and a friend use to level their pets by pet battling each other but one would always forfeit so the other would get the experience. They would do that for hours and get a slew of experience. Since one would always forfeit right away the leveling was quick. I guess one day I will tell new pet collectors how we use to power-level pets on the garrison dailies. At least I got to enjoy that while I could.