That sounds a lot further than 70 miles.

I've biked from Raleigh to the outer banks a couple of times now. I might be able to suggest some campsites, but I do tend to go further than 35 miles/day. I'm not a strong rider, either, but I plug away. Plus I don't mind stopping for a while mid-day, having a leisurely lunch, and then pushing off again. And if stealth camping is your goal, I've found that I can end my day pretty close to dark without having put on many miles just by stopping along the way and taking it easy.

For my part, I planned my routes whenever possible with multiple stopping options, so that if daylight is leaving, I can bail early and stop closer. I haven't had to stealth camp, but on my Raleigh to OBX trips, there were days that I road farther than I wanted just to get to the next campground.