Brent, thanks, but I'm not busting a gut. Managed to do another 29km ride today, although this was tougher - hotter and some saddle uncomfortableness. The bike's doing most of the work on the tough bits and I've been mostly coasting down the hills.
I'll be having a rest day tomorrow and hope to get a short ride on the weekend sometime maybe. It's the saddle soreness that's limiting me now, as the bike is providing the crutch in terms of power because of my limited fitness. It's allowing me to slowly rebuild the fitness, but still achieve getting places in a reasonable timeframe.