i'm sorry you're stuck between such strong opinions, and a little alarmed at your being afraid to approach your husband.
being a momma's boy is a good thing. i'm glad he loves his mom. but being okay with his wife getting yoinked around rather than ask mom to be just a little gracious and accommodating?
so not okay.
i think your tactic of asking your MIL to simply back her dinner plans up an hour or two is perfectly acceptable. i'm sorry she got upset and is being a baby about it. it's not HER holiday- it's a family holiday. what she deserves after guilt-tripping you is for you not to come at all.
and your 'sweet kind' husband has a hitch in his gitalong if he thinks his mom should be 100% pandered to but is pissy about spending time with yours.
the obvious solution is that you go to your (delightfully accommodating) family and he goes to his mother the martinet.
i suspect you're too much on the Pleaser end of the spectrum to be that adamant.
what i hope you'll do is refuse to take any blowback from your husband and lay it out to him firmly and without apology. and do whatever it is YOU feel is the best compromise.
if you can't approach him without trepidation, you have a lot of inner work yet to do. no shame in that. but think long and hard about old patterns re-establishing themselves. it's probably more subtle with this husband, but it would seem that an unhealthy old dynamic is still at work.
i'm not going to see either of my kids this thanksgiving. bummer. i adore my kids (and their women) and would rejoice if they were going to make it here. but i totally understand that they are all in with spending the day with their gals' families, and want them to enjoy it without trying to do hours worth of driving and try to stuff in two huge meals. i'll see them all over the holiday weekend, and a wonderful time will be had by all.
i laid down the law with both families when we had little boys to consider first. i have vowed never to guilt-trip my kids over holidays.
i hope you get to where you can do the same for yourself.
ETA after reading the other responses i'm editing this a little because i agree, going to your MIL without talking to your husband first really set you up to be in the hot seat here. better all round would be to iron it out with your 'sweet kind' (huh) husband and have him deal with his mom. if that isn't going to happen, separate Thanksgiving celebrations.
good luck.
khairete
S.