Unless they have lowered the TMA/CTA since I last looked, the transit round the East of the Manchester CTR has just enough headroom to be do-able and is very pretty. This has to be strictly CAVOK though as there is no room for IMC safety altitude.
Perhaps a silly question, but if you are IR rated and equipped, why not file a flight plan routing direct overhead MAN? A South-North transit through the overhead should cause ATC no trouble at all.