There are many level 70 twinks across the realms, but unfortunately battleground's nearly unplayable since the level 79 crafted pvp geared players are easily smashing the 70's even with full brutal gladiator set. The level 70 arenas are alive, so level 70-only battlegrounds would worth a try. Other suggestion is to make wintergrasp's weekly quests available from level 70, so they could farm some honor points since they can't farm at battleground's.