A word of advice: once you get off the ferry at port aux basques, do not pas sup any opportunity for fuel until you hit the grandfalls windsor/gander area. Especially if you're on a 'Max.
I have a freind who rides a 'Max in NFLD, never goes anywhere without a spare jerry can strapped to the back.
It's not horrible in NFLD as long as you stick to the TCH, but rural and you're taking your chances.
But the run from PaB to Stephenville area is pretty bare. Only two stations along the TCH and closed if you hit them after 6 pm IIRC.
There's a decent little stop at Marble Mountain. Fuel and a Tim Hortons. Good place for a "butt rest" and a hot coffee.
The run up the west side is not exactly scenic either. At least not once you get a decent amount outside of PaB. It's all two lane and through the woods, but traffic is always pretty light and the road is pretty new (IE: smooth). Scenery picks up if you get off the TCH and head up to Gros Mourne Nat park. It also picks up once you're past Gambo. The road up to Musgrave Harbour is well worth the detour if on the way to St John's. It's where you see lots of icebergs, if they're still there this time of year. Getting a bit late in the season for that, but Musgrave Harbour beach is a nice stop. Miles of white sand beach. Keep an eye your fuel if you go up that way....
If you plan to spend any time in NS, there's lots of scenic routes and great riding roads. Back side of the Cabot trail is breathtaking. Here's a PR pic from the Cabot Trail:
I'd ride the Cabot more if I could, the road is pure food for the soul. It's just a pretty long haul from where I live.
I personally like marine drive up the Eastern Shore. It's one of our greatest bike road secrets IMHO and hopefully I'm not shooting myself in the foot by saying that! LOL! The roads are nothing but turns and up and down and it goes on like that for about 3-4 hours once you're out of HRM on the #7. Sherbrooke historic village is a great stop about halfway up for fuel and "butt break" and has a couple great coffee shops. I recommend "Beanie's Bistro" if you go that way. I usually end at the pub in Canso before turning around and going back. Scenery is pure east coast quaint with harbors and fishing villages as old at the 1700's. Marine drive has rough pavement on a lot of it though. Not broken, but rough from repairs. My Venture can almost bottom with 70 psi in the rear shock, I'm betting a 'Max would bottom a fair bit on Marine drive.
If you're getting "monkey butt" on your ride, you're passing right by Lismore sheep farm in River John (NS) and they sell sheep skins (they have a wool shop). I picked up a shearling skin a while back and it makes a big difference with sweat and heat.
I recommend getting a cabin on the ferry if you haven't already. 110 for a night crossing cabin and half price on the day crossing. Well worth it to shower and sleep at night. Daytime it gives you a place to go besides the sitting areas for 6 hours and you can lock up your stuff there instead of dragging it around.
safe travels.