just one teensy problem - the "down" escalator to the southbound victoria line at euston is out of use, leaving you to tackle the fixed spiral stairs. if it's at all busy, use of the stairs is restricted as it can be a bit tricky when it's busy. additionally the most obvious alternative not possible because there's no interchange between northern and district lines at embankment.
if you don't fancy the spiral stairs at euston, take a no 73 bus from outside the station directly to Victoria; every 5-7mn, journey 45mn.