Yeah, if the British remain the dominant power in North America there is probably going to be no United States, likely there will be several countries carved out of the North American territory that Britain controls. To start charting out a post-rebellion world there are key questions that should be answered.
Punishment: A victorious Britain will seek to punish the rebels both collectively and individually. This will likely include imprisoning and executing most, if not all, of the signers of the Declaration of Independence and principal military commanders. Beyond this things get more complicated, parts of the British government will certainly want to do collective punishments (government reconstructions in Massachusetts and Virginia are very likely) but there are British politicians who sympathized with the Americans and there is the very real possibility of stoking another rebellion down the line
Slaves: IOTL roughly 3000 emancipated slaves fled with the British after the war. Without having to flee there will likely be substantially more, add to this that emancipating the slaves of rebelling slaveholders could be an appealing punishment and there is a substantially larger free black population. Will the British still pursue a plan of resettling them in Africa (OTL Sierra Leone), will they allow these free blacks to remain in America, will they try and split the difference (Florida would be British too and relatively uninhabited)
Native Americans: How serious are the British going to be about the Line of Proclamation, now that they've seen the length that the colonists will go to fight it?