Yes, I am planning to head out to some dealerships and sit on some bikes. Yes, I do pretty much know what I want.
But before I talk to salesmen, I'd like some advice from all you helpful and experienced type guys. (And you too Lori!) I hope some opinions from real-world experience will give me information to counter an over-enthusiastic salesman's spiel.

And I don't think the dealership would let me take each bike for a couple of days to thoroughly test ride.
My current bike is an 01 Intruder 800. I like it a lot, but there are times it feels small, and when I'm on a long 2-lane just cruising along I feel like the rpms are too high and there's a lot of buzz and vibration that gets tiresome. I'm constantly hunting for that non-existent sixth gear. It's also old, and while I've put money into maintenance, I'm not sure how much I trust it for a long distance trip. I haven't yet firmly decided to give up on Bike and get something different but the shopping is interesting.
I've been spending my evenings reading reviews and watching ride videos and paging through cycle trader. I'm finding my favorites to be the Vulcan 900, the Vulcan S, certain Boulevard models, and some of the Rebels. I don't want a big heavy bike that I can't easily take care of and move around. I'm not really drawn to the dual sports or the sport bikes. I'm also not into a huge amount of chrome and giant exhaust pipes. I don't like fairings, excess plastic, or the crazy fender that points at the sky. In fact, if I were to buy a bike tonight based just on looks, it would be a Rebel or the Vulcan S. But I have a few things I'm wondering about.
Bike capacity - would the Vulcan S with the sixth gear, even though it's only a 650, be more better for spending a few hours at 60-65 mph without feeling like the bike is over-revving? Are bike transmissions built differently enough that a newer bike with just 5 gears wouldn't feel like it was working too hard? Do any big guys ride the smaller bikes and can you say if a 500 or 650 cc bike would have enough power to haul my fairly buxom carcass around? I don't feel any lack of power in my 800, (I tried once and it easily hit 80 mph but it wasn't fun with all the buzzing) but I'm afraid a smaller bike might cause the polar bear on a tricycle effect.
Gravel roads - Bike doesn't like gravel roads! 🥴 We managed when we had to, but it was sketchy. To be fair, I rode all summer on only one carb so slow speeds were an issue. He might do better this year now that the carbs are done. But there are a lot of gravel roads around here and I'd like to explore without the skittishness. Is the ability to handle gravel a function of the bike's geometry? Would I have to have the knobby tires and longer shock travel of a dirt bike or dual sport to head down those back roads? I'm not talking BDR stuff, just normal, relatively maintained county roads that I am accustomed to traveling at 60 mph in my truck. Or can a cruiser handle roads like that, and I just need to have a bike that can handle slow speeds without snorting over it, and spend time practicing?
Distances - as I get more comfortable back on 2 wheels again and relearn the skills I had 30 years ago, I want to go father. I'd even like to go all the way up across the Mackinac Bridge and explore the UP. What are your experiences in using a smaller bike for a road trip? I'm not talking Iron Butt stuff, just maybe 200 or at most 300 miles in a day, taking my time and exploring. Would a 650 with a good seat would be sufficient, or would a 900 be necessary to keep me from feeling like I've been putting up small bales all day?
Inquiring minds want to know.