Did you read the dimensions of the fabric?  It is only 15" wide.  If you feel the need to cover your junipers, loosely wrap them with burlap leaving an opening at the top.  Junipers are not particularly susceptible to winter injury as long as they go into winter fully moisturized.  Damage from rabbits and deer is more possible and fencing will eliminate that problem.  https://extension.umn.edu/planting-and-growing-guides/protecting-trees-and-shrubs-winter

It is hard to have a neighbor like that.  The fabric cover is only 4 feet tall so even if you could fit your junipers into it, the tall one would still be open.  There is flexible plastic snow fencing on rolls that could be used for several trees in a row.  I use it to fence off a large area in my yard and hold it up with stakes.  If you could put in some tall stakes and then put up one row and then a second row on top held in place with twist ties securing the two together, you could get the height you need.  Maybe you will be lucky and there will be less snow this year but otherwise try this process.  This plastic snow fencing is not very expensive.  Also, try consulting personnel at your local hardware/big box store and see if they have any additional suggestions.  Good luck.