Hope you have a good tow. Had to take mine up there last year.... Then I did empty as much fuel as possible out, (in my case diesel). I take your point about storage but I do try to tow as empty as possible on a long journey simply because it seems pointless using car fuel to tow dead weight.... it will be safer and cheaper not to!
Can you not give a few friends some gallons to store? I have towed mine full and my Jeep Cherokee certainly notices the difference
As for nose weight…. as a guide, for your size of boat, the nose should be heavy to lift for one person but not hernia heavy! Good luck with the bathroom scales.... After I used mine for that purpose, they said I only weighed 2 stone the next time I used them! We have a nice new set now!
I'm sure it will all work out!