I do this quite often - relatives in Guernsey - and the best routing for me is via Catherines Point IOW then direct to BOLRO and then Guernsey. This keeps you out of the airway and DA so you can fly high (which gives you longer to talk to people if it all goes quite at the front), Landing and parking are cheap in Guernsey and the aero club has some good hotel deals (and there are many B&Bs), Plus fuel is cheap so don't leave UK with too much, before filling up, and then dct to Cherbourg. (If you are an AOPA member you get an additional discount off the fuel too).
The only way back from Cherbourg is up the VFR route but of you do that at the w/e and the DA is not operational that's useful.