Since you're using TP I assume you have a PM/HRM in which case Training and Racing with a Power Meter by Coggan & Allen is required reading. I haven't seen any off-the-shelf training plans for long-distance multi-day events, so as far as I know, you'll have to make up your own plan or pay someone to do it for you. All we have to do is crank out steady watts for a few days, so I don't think it needs to be too complicated. Here's what they recommend for the
PAC Tour. Here's another one from
BC Randonneurs. Pretty simple stuff.