Lucy,
You're only as old as you feel. If your husband thinks he's fit enough, mentally capable enough, and either possesses the skills or, is willing to be taught the skills of handling a large coach like that, then, you can go for it. Now, I'm certainly no authority just what states have, or do not have any restrictions on that length of a coach so, I really can't help you there. I can tell you that even here, in some areas of So CAL, there are restrictions on where you can actually drive vehicles over 40'.
As I understand it, there's more of those spread out, around the state. So, if there's the same type of restrictions in other states, well, you'd behoove yourself to maybe find some sort of printed or, on line guide that shows or labels those restrictions.
As for campgrounds, yes, you will find some that will not be able to accommodate that length. Again, do not let this be a deterrent to your travels. If you plan on any given route, through any particular state, or, in any particular area of a state, you can most likely find any info you desire on line or, get a hold of that states road maps or, set of restrictions etc. Information is everywhere these days. All you have to do is, dig a little.
Handling such a large rig might be intimidating so, I'd definitely do some long test drives, in all kinds of conditions, if the seller will allow it. Big is good when full timing. You get on each others nerves less. But, BIG costs you in all kinds of ways. Everything is bigger, tires, engine which, will cost you more in maintenance--more oil etc. It all depends on your outlook. If you pay to have all the maintenance done already, it might not be any sort of shock to you.
Before I'd jump into that monster, I'd maybe cruise on over to an RV show of some sort near you and, take a good look at the smaller units, say a 36'-40' unit and see if any of them draw your fancy. They'll handle a tad better and, will be a tad easier to find camp spaces in both camp grounds and RV parks. All I'm saying is, keep an open eye and be well educated prior to making a decision. Once you're informed of all the options, both good and bad, then you'll be better equipped to make an informed decision. Good luck.
Scott