Photo edit - take a dog (subject) from one photo and place onto snow scene background

I have a photo with dog as subject against a neutral background (kitchen floor)
Need the background removed and replaced with a festive snowy scene/scenery
New background must be slightly out of focus
Entire photo must look realistic, as if portrait taken in location, with depth of field, no cut and paste marks, pixelling etc
Finished JPEG, size/resolution for printing 6.8 cm x 6.4 cm @ 803 x 756 pixels or better
Must also be 1cm high strip at bottom for text (I will add this later)
Photo of dog attached, example of snow scene attached (wrong resolution I think)
Quick turnaround needed please
Please allow 24 hours for response