A couple of days before is no problem. The self-discharge rate for NiCds is abysmal compared to Alkalines... but it takes more than a week for it to drain enough to worry. Average self-discharge is appx 1% per day. (old tech batteries... newer may hold better.) Just be sure you do an ESV check often enough to be sure you've still got enough to continue flying.

You might want to consider a more potent charger... The 50 mah rate of the wal-wart is marginal for a 1100 mah pack. Its actually down in the "trickle" catagory, which means you could safely leave it on charge a LONG time. (like forever...) 100 mah would be a much better overnight rate.

I'd bet you have more than just one R/C system... and more stuff to charge.
I use a Hobbico MultiCharger which will do 4 packs at once at a variety of switch selectable rates. Handles 1 to 10 cells (maybe more... I don't have a pack with more, so didn't pay attention.) and will do any 4 different packs at the same time. (limitation... the lower rate positions won't go above 100 mah, the 500 mah position doesn't go below 50 mah.) Its 25 mah rate would be a guaranteed good trickle rate for the 1100 pack. You'll never burn out a pack at C/40.
I'm currently charging a 700 mah 4-cell RX, a 270 mah 4-cell RX 1200 mah 1-cell Ni-starter and a 750 mah 12 volt gell cell on it. The charger does quite well.
Note that it does NOT peak detect... But the price isn't bad for what it will do.