That's a hypothetical question... how far is a Ju 88 able to get into enemy airspace before getting shot down due to lack of speed, alt, and defensive armament? 
Someone might know who has a strong RAF background studying 1941/1942.
(Referring to it solely within the confines of the game is a different story as the Allies had no P-51-D, Typhoons, and Yak 9's in the early war of that time. It might be some interesting experiments for say, teams of 20 vs 20 to put up a historically accurate scenerio in the EW or AvA arena with timed takeoffs and contact times and altitudes of historical accuracy and give it a shot. If you are takling about LW--they are going to get BBQ'ed in a few passes.)
In Germany's magazine "Signal" of the day, they printed the lopsided graphs of the ranges of German fighter's and German bombers vs the ranges of RAF fighters and RAF bombers (not letting the cat out of the bag regarding newer/better medels in early production or models still on the drawing board.
The "Goliath" model was going to be one of Germany's longer range/heavier loadout models (in comparison to the ones we know and already have) but suffered in early trials do to the extreme overload on the engines and tendancy to catch fire.
The larger Heinkel and Dornier models some folks are refering to that did have a role in WWII (especially the BoB) were as quickly recalled from the front as the Stuka because of high disabilities to defend itself once most of it's escorts were "busy". Even the '88's with their ventral and two dorsal gunners had huge difficulties with small machine guns vs fighters with cannon and .303 mg.
Even so, a mass of JU-88's, some Heinkel 111's, some ME-110's with Messerschmitt and FW escorts did massive damage to UK southern ports and strategic military targets during the BoB.
ROX
