If the distance allows for an indoor gateway you could look at the TTIG. Or if you don’t mind hacking with an RPi and have experience creating your own solutions based on it, search eBay (LoraWan EMB- LR1302 - mPCle-868MHz | eBay) for old Helium hardware which can be reused with some effort. However there is no guarantee you’ll be able to get it to work without a lot of effort.