Go for it, mate! I used to do a lot of cycle touring with a tent on the back of the bike when I was younger.
One of the sweetest was a coast to coast along the Great Glen Cycle Route from Fort William on the west coast of Scotland to Inverness on the east.
Not a long trip by any means, only about 80 miles, but there was so much crammed into those 80. It follows canal paths up from Fort William, spills out into Loch Ness at Fort Augustus, managed to rick my knee on the way there, so laid up at FA for a few days, watching yachts traversing through the middle of Scotland whilst sitting in a decent pub, then a stint on the high ground above Loch Ness, didn't spot the monster, then through some leafy glades and forests on the run into Inverness.
Like I say, just 80 miles, but it was a good 80 miles!
That certainly sounds like something I'd look at doing at some point. The one I'm hoping to do this year is the Trans-Pennine Trail, which runs from Southport to Hull. It's 215 miles and I'm thinking of taking a week to do it in. It depends on a number of things like getting the time off work, getting the time to train, talking the wife into letting me disappear for a week etc, but fingers crossed.