Here’s a thread on my message forum about online casinos that do not reshuffle after every hand.
http://www.blackjackinfo.com/bb/showthread.php?t=132
It shows a few examples of online casinos where card counting can work, even though it’s still only a small advantage because of the limited number of hands between shuffles.
For playing single deck, the Wizard of Odds does have an excellent list of strategy variations for use based on the particular cards in your hand. It’s in one of the appendixes under blackjack at his site.