Before I start, I know these engines are renowned for leaking oil, so I'm not panicking, just after some advice on whether it's an immediate issue or something I can sort over summer when it's easier to get time!

So my engine has started leaking oil, it goes from around the full mark on the dipstick to around the halfway mark over the course of a couple of weeks (so a month or so for whatever a 'full' engine load is).

There's always a couple of splashes of oil under the car when I park up, and it looks like the front diff has a coating of oil so it's coming from somewhere near the front of the engine I reckon.

Could be front crank seal.....

If it is leaking a few litres in the course of a month - I wouldn't wait until Summer.

Got to agree with the man @Saint.V8 there if its losing in that sort of quantity who is to say it won't just totally fail as a seal and dump the lot at 70MPH?
Handbook says check every 250 miles and if closer to full than add-oil only add 1/2L, if the other way round add a full litre, but check again after 5 mins.

Or is it coming from the front cover and dripping down? The v8 seems to leak from just about everywhere!

If there ain't oil under it there isn't any in it

Likely the front cover is leaking, maybe the crank seal as well as the sump..

Mine leaks out of all of 'em!!