Hi William, appreciate seeing your question here. It's a pretty easy one to address, but I will add in the caveat that any useful answer really depends upon from whose perspective you are looking. The only plan that mattered up until Derby was that of Charles Edward Stuart, and then from 'Black Friday' on it did not matter so much. Stuart aspirations were always focused on a restoration to the thrones of all three kingdoms, which meant that crossing the border and heading to London after marginally securing Edinburgh was a foregone conclusion in Charlie's mind. Some high-ranking officials in the Jacobite 'Council' tried in vain to convince him that staying in Scotland and consolidating power and resources north of the border was the only viable way to manage the rising, but Charles Edward would not hear it and insisted that the march to London was part and parcel of his family's destiny. It can be argued to good effect that that moment was the most consequential turning point of the eight-month campaign.
His plan was simply to outmarch and outmaneuver the British armies in England and to enter London while facing as little resistance as possible, establish provisional control of government operations as they had done in numerous towns and burghs in Scotland, and then wait for the anticipated support from Northern England to show up. With the lightning coup proven and settled, after declaring James III & VIII as the rightful monarch, French assistance would be welcomed and likely provided. With the Auld Alliance once again rekindled, the hard work of reshaping the government would be attended to. That entailed Charles Edward's wish and plan.
I will spare you counterfactual narratives that linger on what could have happened and instead bring us back to Derby on 6 December, when most of the prince's council undersigned a letter stating that under no circumstances would they be part of any enterprise that was to continue the last 125 miles toward London. There is some excellent coverage of the lead-up and response in some of the suggested titles below, and in fact I am due to write a chapter in a forthcoming publication about archival evidence connected to the debate between Charlie and his top-level aides during their short stay in Derby.
• Frank McLynn, The Jacobite Army in England 1745: The Final Campaign (Edinburgh, 1998).
• Christopher Duffy, Fight for a Throne: The Jacobite '45 Reconsidered (Solihull, 2015).
• Brian Stone, Bonnie Prince Charlie and the Highland Army in Derby (Derbyshire, 2015).
• Jeffrey Stephen, ‘Scottish Nationalism and Stuart Unionism: The Edinburgh Council, 1745’, Journal of British Studies, 49:1 (2010), pp. 47–72.
Hoping this covers the gist of your question, but feel free to continue the conversation below if there might be something else with which I can help.
Yours,
Dr Darren S. Layne
Creator and Curator, The Jacobite Database of 1745