Dear Mr Ergo
You can always sell the 32s at a reasonable price to recoup a certain pile of tuppence, but I would suggest holding off just in case the clearance is really really tight with the 35s and the fenders. I've had fairly close tolerances with an old bike with 28s and some fenders, and it generally was ok, but just do be aware not to have it super close as it just increases teh risk of jamming stuff in there, especially on a dark commute where we dont see stuff.
Hey, for 1.5mm more on each side, is it worth it? The answer is yes given that as you have already ordered the new ones ;-) but for commuting, I've certainly grown to like the 37 or 38 1.5in tires Ive had on one of my bikes for years, again, especially in the dark on our pretty pants roads here in Montreal, so I get wanting wider.