Hi Alex,
As an idea of the challenge, I've seen SN2012cg in NGC4424 in Virgo on two of the past three nights, using an 8" dobsonian scope. The first night was from a dark site, and the SN was bright and easy, with the faint smudge of the galaxy behind and around it, and two other galaxies (NGC4417 & NGC4442) in the field of view. The second night was from suburban Melbourne, and I could see none of the galaxies, but two stars, one of which was the SN, were just barely visible with averted vision through the city skyglow in the appropriate field. That's for perhaps the brightest SN of the year at 11.5-12th mag! In fairness I wouldn't fancy showing anyone the SN in Melbourne, because it was not just "there" in the eyepiece (say like a bright star cluster), it's hard to see even with time and with practised averted vision. From a dark site, or with a larger scope, I'd say definitely yes!
A good image of this SN is at:
http://www.astrosurf.com/re/sn2012cg_20120612.jpg
The three-star asterism at lower left was a great guide, and the faint two stars were the SN and the field star just to it's upper right at the one-o'clock position.
People were seeing the M101 SN with binoculars, but I moved to the southern hemisphere just before it went off so I never saw it!