Very slow iCloud restore of data to a new iPhone

Hi - i backed up my old 6s+ to iCloud, 148G of data...

The restore process was started by the phone shop via wifi, transferred to 4G whilst i drove home & is now continuing on my home wifi (BT 55mbps/18mbps) but its taking an age & by my calculation is transfering at 2.1g per hour? Am i really staring at a possible 50hrs to complete this? The back up itself took 8hrs...pls give me some sane news!

thks