It is well known, that the range of the eufycam is quite HORRIBLE!
We have discussed and mentioned this at kickstarter for months.
There had been an update which helped a lil bit, but the range still sucks for most of us.
In my personal case, the max range i can get is joking 12 meters (39 feet) with just one wall in between and therefore i also had to move the homebase several rooms to the KITCHEN!, a location where it normaly doesnt planed to be, and also needed to buy a wifi range extender to get the homebase online there! I even had to buy a special "wall bracket" to get the homebase at a higher and best possible location to get my several cams online at all! See here:
300 feet?! (91 meters) Are you nuts?! sorry ... lol ... not with eufy cam to eufy homebase, no way ... maybe when you live at the north pole, without any other people, networks, walls, interferences and with direct visual contact to the homebase. Maybe ... but not in a real life situation, sorry.
Beside the fact that eufy cam uses its own wifi for security reasons and you just can't use a regular wifi range extender at all, thats the reason why we all wait for the EUFY CAM RANGE EXTENDER so bad and since 4 months already. Actually it is planed to be released in April-May 2019 , which means probably end of 2019 This will be the only way to EXTEND the range of eufy cams to then hopefully useful ranges for everyone!
I just hope eufy will offer this range extender for free to the backers as compensation for the horrible range or at least for a very fair price, which is not made to made money out of it, as it is not customers fault that the range of the eufy cam is often unacceptable.
Remember: In the kickstarter campaign there was a much wider range promised and in my case i invested already about 1500 € (1700 USD) in eufycams and it would be nice if they would finally have a useful real life scenario range then, if need be with the range extenders. (which brings unnecessary additional electricity costs)
Don't get me wrong. The eufy cams and homebase and app are great and have a lot of potential, and i love em, but they are far away from beeing perfect, especially the ranges. But eufy is still doing its best and hopefully keep on bringing updates, improvements and fixes.
Addition: As you have mentioned eufycam E in the topic, i would like to say that my above explained experiences are made with the regular eufycam and eufy homebase. Don't know if there is a difference between E and NON-E when it comes to the range.