Thanks, indeed it does; a lovely setting too
I went for a bit of a walk in the (relative) cool of the evening with one of our earlier mentioned Uniden phones. Its range is variable depending on what structures interpose on the signal path. I had as much as 60 metres down the street with only the walls of our house in the way. However it fell back to about half of that once there was a fence or another building to add to the existing signal barriers.
In everyday use we have a couple of these in the backyard shed of our 25 x 40 metre town block. The master unit is on the most remote room in the house from the shed, and the path is sufficiently reliable for phone communications although it can chop in some instances, which suggests it's on the limit.
If I transpose this observation into your specific situation, I am inclined towards predicting that this particular system could work if it were not for the building (shed) between the two dwellings. A trial would be needed, but I think it's a marginal path at best with the units we have here - assuming that they are still available.
Now it may be that there are other cordless phone systems which give a greater range - ie a better performance when there are structures in the signal path. My older Uniden cordless phone which came along when we left the farm is extremely good in this respect and offers 300+ metres coverage in most situations. Alas it was replaced in the product line by the ones we now use, and it didn't offer the intercom facility anyway. I would suggest that you see what you can find on offer in an electrical store where people can give a reliable and honest estimate of what you might expect once you outline your specific needs and intentions for the equipment.
Your picture suggests a rural location, which if it is indeed so, again raises the possibility that a pair of UHF CBs on a very low power setting using one of the 'new' channels and CTCSS options could be satisfactory.
However I think I have possibly explored the options as far as I should within this forum. If you wish to follow up with a PM please feel free to do so, and I will he happy to try and assist in whatever limited way I can. In the meantime other options may be presented by the members of the forum and you should keep the door open for that possibility.
regards
FOR
Edited to suggest that Bushfiva's suggestion is another possibility if it offers sufficient range / power to get around the building in the middle.