Rounding Vectors based on length of line

I am seeking a function that can round the angle of a vector based on the length of line of that vector.

The parameters I require are as follows:

1. If the length of the vector is less than 250 then round the respective angle to the nearest 10 seconds
2. If the length of the vector is between 251 to 500 then round the respective angle to the nearest 5 seconds
3. If the length of the vector is greater than 501m do not round the respective angle

The vectors are in the following format:

295° 41' 17" 949.393

Note there is a space after the ° and ‘ symbols and furthermore the angle and distance values are in separate cells.

Currently I am using the substitute function to format the angle without symbols i.e. 295.4117.

See below.

=SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(A1,"° ","."),"' ",""),"""","")

I then round these values using the MROUND function which requires individual analysis of each vector and therefore is time consuming.

Any advice or assistance to speed up this process would be much appreciated.

Thanks in advance.