It is probably hard to be certain, especially with there now being 7 leagues.but given that you are palace 26 , I am not sure you will notice much difference.
The chief drawback of being in a clan of 1 is that you will pay tax of 10% of your silver to the konung, roughly at least once every 24 hours.
In order to compete in CvC you need a minimum influence of 5 million, which you probably have anyway.
Its not the resources that you need worry about either, the hardest thing to get in a clan of 1 is the scrolls and the influence in order to build a stronghold and of course thats not the end of matters.
You will still need more scrolls to upgrade the stronghold, and having a stronghold will just bump up your influence,so you will be back where you are now, in a clan, where you find the check points too difficult to reach.