First, it's absolutely smart to consider what you will do next. I would estimate for every cruiser who finishes life on the boat in their 80's there are a few dozen who eventually move back to land. So, a future on land is the norm, not the exception.
As far as being a landlord...if you are asking, it's probably not for you. By that I mean if you have experience with being a landlord, you know the pitfalls and are better equipped to avoid them or at least
weather them (can't avoid them all). If you've never been a landlord and your first try is the nice home you want to return to while doing being a
remote landlord, the odds of running into major problems are high. Most successful landlords start with a
cheap house nearby where they can manage everything and do a lot of the
repairs themselves. Worst case scenario, the cheap house takes a beating and because they are doing everything themselves ongoing costs are kept low. In the end they lose a little but not a huge amount. Later if they expand to a larger scale, they can start farming out
marketing, vetting of renters and
repairs.
The one possible exception is if you expect real estate prices to skyrocket over the next 5-10yrs and you are dead set on a particular area. Of course if you can predict where prices will skyrocket, you will be rich and all this discussion is moot. (Speculation: My thought is housing prices are being propped up by govt programs pushing cheap loans. Most of the prices already accounted for the low interest rates, so at best, I expect little to no growth for several years as there isn't room to take interest rates lower. More likely is the rates will gradually be pushed back up and that will drag housing prices down, particularly in hot markets.)
Assuming you are willing to move to low to moderately priced areas after your cruising is done, I don't see a lot of advantage to trying to keep a house as you will be able to use the
sale proceeds to buy a house when you are done cruising.
I would suggest setting the
money from the home
sale aside in moderate risk investments. You don't want to go risky and have the investments drop by 50% just before you move back to land but you also don't want to lose to inflation by accepting a very safe 0.5% return.