In my darkroom, I have (at the moment) only cold water. The water temperature is appr. 12.5 Celsius (54.5 Fahrenheit).
When using liquid emulsion (Foma), I am aware, the the temperature of the water, when washing the paper must must not be too warm in order to avoid bubbles in the emulsion. However - is there a problem, using too cold water when rinsing? In my case, I would like to use running tap water - but is 12.5 Celsius too cold? And in case it is not, I assume, that the paper should wash a little longer?
Washing is a soaking out process. If the water is too cold it will take much longer to do the job. I believe you are better off to use 5 one minute soaks in water about 20 deg C.
Ilford says washing double weight FB papers above 5C/41F should take about an hour. Looks like you're in that ballpark.
My experience with liquid emulsion is that the longer the wet time, the more chance of bubbles and seperation. I'm sure this depends on the base material and handling. Just handle very carefully.