Going stupidly into a century on crap mileage - doable?

[zoom-zoom]

So it's 6 weeks until the first century of the Summer. A year ago I was putting in >100 miles/week and doing long rides of 46-65 miles. Now a good week is about 50 miles...for a multitude of reasons. I've just completed a half-marathon that took my focus for the Spring, but mostly because I've sort of lost my riding partner.

My DH is training for a 100 mile mountain bike race in June and bought a Mukluk this Winter. I really regret encouraging either of those things, to be honest. He's always off riding trails and training. I feel a bit cheated on, truthfully. He knows it and he's feeling guilty--now that he's in Moab and Fruita for 8 days, but it's sort of a too-little-too-late thing and I'm irked. We went through something similar before he bought me my road bike...and everything was great when we had that to do together, but I am in no position to mountain bike with him most of the time...because I'm horrible at it and slow and it's not something we can do with our 11 year old DS (we bought our road tandem so that we could have him along and not have to pay for childcare all the time). So he used to abandon me for long rides with friends on his road bike...then I was able to join in, but now he's off with friends on mountain bikes and mukluks and I'm feeling really hurt, again.

So I spent the Spring sacrificing a lot of rides, since I really loathe riding alone. And the really irritating thing is that the group he rides with are a bunch of people who also loathe riding alone, yet it's OK for the wife to have to do that. And the rides are generally at least an hour away, so it's even more time that he's gone.

I bailed on my Summer Duathlons plans and am now not sure I'm going to be ready to do a century so soon, either. I'm frustrated, because I feel like I'm sacrificing my needs and wants for him. He turned 40 and is in some ridiculous midlife-crisis state where he feels the need to race himself to death. Somebody please smack me if I act like such a fool in a year.

What I really want to know, after my oversharing, is if it's even possible for me to do a century if I'm only doing 30 milers as my "long" rides 6 weeks out. Some weeks my mileage is that single ride. It's sad. I have decent running fitness (20-30 miles/week for the past couple of months), but have no clue if that would carry over on the bike. I did 3 centuries last Summer and also rode across the state (147ish miles), but I was well-trained for those. Last year I pedaled >4000 miles...this year I'll be lucky if I manage half that many.