Again it probably depends a bit on what they are used to, on a lot of ground that's shot over regularly they don't even leave the wood either break back through the beaters or break out at the side and enter the wood again behind the beating line, in small copses they may leave but are likely to return quite quickly.
Roe are very quick to except any type of activity that happens on a fairly regular basis, look at how many live in urban environments, people traffic noise etc.