I am not familiar with Hasselblad, but I shoot medium format IR with Bronica (different in detail, the same in principle).

1) you don't need extremely long exposure times with IR photography. The typical exposure times are in the area of "just not quite handholdable" - my typical exposure is 1/15 of a second at f 16.
So you definitely want to use a tripod, and perhaps lock your mirror if your camera allows, but do not need a special remote release of the lockable kind.

2) there are just two IR sensitive films manufactured as of now: Rollei Infrared and Ilford SFX200. Neither of them reaches very far into IR when compared to a converted digital camera, so you have to be careful with your choice of filter - if you go too far you risk an empty film. The gold standard of IR film photography seems to be Hoya R72, which is what I use.

3) the emulsions of IR sensitive 120 film are the same as for 135 film, so metering is in theory the same. But - and it is a big but :) - there is no exposure meter available for IR light only. So you have to measure the visible light, and bracket. For a sunny day and R72 filter the difference is usually about 5-6 stops.

Here is one of my photos on flickr - follow the link for exposure information. I used a tripod and R72 filter, but not a special cable release (just my regular one, and the MLU lever)