Apologies for the lengthy reply, though I do have quite a bit of experience in this regard, though admittedly with smaller boats. But, I've done the trek from east coast to west coast for boats 3 different times over roughly 5 years. That being said, each boat that I purchased was considerably smaller and nowhere near as wide as one with a 10'7" beam. The first two boats were for 21' Arima's and then the last one was back in October of 2021 for my current boat, which is a 2004 Grady White 228 Seafarer, all of which have an 8' beam. I had no issues with driving back and forth across the country multiple times and the first time, I even did the trek roundtrip where I drove from Seattle out to Maryland, bought the boat and then drove it back out to Seattle, several of those days I was putting in 1,100-1,200 miles of driving per day. The other two times, I flew out, rented a truck/U-Haul and then trailered the boats back from there. It really just depends on what you want to do, what your comfort level is, how much the savings are, is it worth the drive to you and so forth. It sounds from what you've said, that you're going from the east coast to the west coast? If that's true, you're looking at close to 3k miles, of which my last trek was 3,009 miles total. I didn't take the most direct route as several highways back on the east coast do tolling and I didn't want to have to pay for tolls with a dual axle trailer, so I added probably a couple hundred miles total onto my trip to avoid those. The trek itself isn't too bad at all if you've got decent weather, you're paying attention, you take your time and go slow, etc. Although it is quite exhausting mentally driving defensively the entire time, making sure you're keeping the vehicle/boat/trailer in your own lane, looking for wildlife or other animals in the road, making sure other vehicles are paying attention and aren't drifting into your lane, checking your height on overpasses and gas stations and so forth. If you're looking to save a few bucks, haven't done the trek before or are looking for a bit of an adventure then by all means do the trek yourself. If you're going through Montana especially, but in general as well, I'd recommend getting hotel rooms reserved ahead of time as well as figure out how far you want to drive each day. You don't want to have to drive 8-10+ hours in one day then come to a small town without any hotel rooms available and be screwed... been there, done that.
The width of the boat/trailer, while definitely being wider than my boat/trailer, isn't much bigger than the ARFF trucks that I drive for a living as a firefighter, and I have no issue with keeping those inside of the lines. That being said, I just turned 39 a couple months back and I see you're 74 years old. My father just turned 75 years old and I can definitely speak for him in that he wouldn't feel comfortable doing the trek by himself, and that I imagine he'd rather have it done for him. You've just spent I imagine well over $100k for the boat/trailer/motors and I don't think spending an extra $5k-$10k to have it shipped out here would be a dealbreaker. That being said, there have been a few issues with shipping companies damaging boats and other vehicles in the process of being shipped. My neighbor had his Grady White 270 Islander shipped out here from Florida and the company ripped the hardtop off the boat from a low hanging tree trunk. It was several thousand dollars worth of damage, of which the company paid for most of it, but I believe he still had to pay a couple thousand dollars out of pocket on top of the cost of the transport. There was also another member on here that paid a company to ship his boat out here for him and then they ended up driving in a snowstorm and rolled the boat over in the middle of a highway, I believe totaling the boat. So, if you do decide to have a shipping company ship your boat for you, make sure you pick a good one that won't likely have any issues. I did the treks myself for a number of reasons, first would be that the first two were considerably cheaper if I did them on my own as opposed to having a company ship them out here for me. Every time I looked into having a boat shipped, it was going to be at least $4k-$8k+ and the first time I figure I spent around $1,800 on my own. Second, was the time factor in that during the spring and summer is when they have the most business, and each time it would take them at least a couple weeks to get to the boat and then another week to have the boat shipped out here. I didn't want to wait that long for several different reasons but I think the third reasons might be the most important and that's the fear of the unknown. As mentioned before, what if the shipping company rolls the boat, runs into something or there's considerable damage? I always like being able to decide my own fate in that regard to where if there's an issue, I want it to be a result of my own actions. Not someone being an idiot and totaling my boat because they made a dumb decision and then me having to deal with the repercussions of their decisions as well as feeling completely useless from 1k+ miles away. Ultimately, and as stated above, it depends on your comfort levels, though it sounds more like you might want to have the boat shipped at this point. Check around online, word of mouth and good reviews for a shipping company is a good place to start. If you have any other questions, you can always PM me, and either way you decide on doing things, good luck with your potential purchase.