While always betting in proportion to your advantage, your maximum bet when playing one spot should be no more than five units. The next increase would be to two hands of five, maxing out at two hands of six. Good advice then, good advice now.
Revere did not have to compete against 6 and 8 decks of play...Among other problems that this causes to the player, is the fact that the advantageous situatiions occur far less often then they do in a one deck game.
This requires that you raise your bets from 1 unit to 20 units to eliminate the built-in 0.5% advantage that 8 decks gives to the Casino and then construct a 1% advantage for yourself...Increasing your bets from 1 to 5 might give you an even game, but there would be no profit margin and you would be playing just for the hell of it, and at considerable risk from standard deviation also.