Leaving the car at home and CX racing - talk me out of it

OK, I know it's a bit early to be thinking about cyclocross season but I'm about to have a bit of a break from the bikes as our family grows a little so I'm looking towards CX as the next thing on the calendar. As I don't like to use the car if I can help it I'm thinking about riding my bike to and from some 'cross races this season but I do have some reservations about doing this. All of the races that I'm thinking of riding to are about 30 (fairly flat) miles from where I live, with the exception of one which is only about 15 miles. Here are my concerns and thoughts:

I might not be able to carry spare wheels - I don't have a pit bike but I do usually have a spare set of wheels in case I flat during the race. I only keep a spare set of wheels because I'd be annoyed if I got a flat after one lap and had to drop out of the race, having gone to the effort of getting there/getting kitted up/etc. etc. Last year I only needed them once and that was due to a problem in practice rather than the race itself. I think if I was having a decent spin out anyway (to get to the race and home again) I'd be less annoyed if I was unable to finish. I'm not concerned about different tread patterns or anything like that; my 'race' tyres are an 'all-round' tread and my spares are not even CX specific.

Tyre wear - 60 miles on tarmac might not do my knobby CX tyres any favours. They not an expensive high-end tyre though so maybe I shouldn't worry (or maybe I'm worrying about nothing anyway and the they'll fare perfectly well). Alternativly I could change tyres when I arrive.

Carrying stuff - Even going light I would need a certain amount of stuff that I'd have to carry in a backpack (I think; I could put a rack and pannier on and remove it to race I suppose). This would mainly be clothing and food/drink (and maybe tyres as above). A track pump is always nice to have at 'cross races but I'm sure I could either find one to borrow or cope with a mini-pump for CX presures. I think I can cope with 30 miles at a time with a backpack on as long as it's not too heavy. My frame has bottle-cage mounts so I can chuck on some cages to keep hydrated on the way there and take them off to race (or leave them on if the course doesn't require shouldering the bike). What I don't want to end up doing, however, is having to do a lot of stuff to the bike before racing. I can handle unbolting bottle cages but I don't really fancy having to change tyres and remove a rack too (and the reverse at the end of the race).

Mud - This is the one I'm having most difficulty with. By the end of a race the bike can be so full of mud I sometimes wonder how I kept it moving at all. The worst of it can usually be poked out from the tyres and cranks but the rear mech is a bit more difficult. Maybe it will clear up when I get out of the mud an have done a few miles on tarmac but I'm not confident of this. I could take cleaning kit with me (a spay bottle and brush perhaps?) but I'm concerned about the extra weight in my bag. Keeping warm might also be an issue but I suspect this will be OK providing I take sufficient clothes.

Finally, I'm not sure if I have the stamina to ride 30 miles before a race but I guess there's really only one way to find out. I'm riding 'cross for fun/fittness and never finish high enough for any points so losing a couple of places is no big deal but I don't want to feel like I'm way off of my best pace. I'm less worried about the ride home; I'll just plod along and make it eventually. It would really reassure me if someody else is doing something similar already but otherwise any advice is greatly appriciated.